HOME

TheInfoList



OR:

The history of the
United States Army The United States Army (USA) is the primary Land warfare, land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of th ...
began in 1775. The Army's main responsibility has been in fighting land
battle A battle is an occurrence of combat in warfare between opposing military units of any number or size. A war usually consists of multiple battles. In general, a battle is a military engagement that is well defined in duration, area, and force co ...
s and military occupation. The Corps of Engineers also has a major role in controlling rivers inside the
United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
. The
Continental Army The Continental Army was the army of the United Colonies representing the Thirteen Colonies and later the United States during the American Revolutionary War. It was formed on June 14, 1775, by a resolution passed by the Second Continental Co ...
was founded in response to a need for professional soldiers in the
American Revolutionary War The American Revolutionary War (April 19, 1775 – September 3, 1783), also known as the Revolutionary War or American War of Independence, was the armed conflict that comprised the final eight years of the broader American Revolution, in which Am ...
to fight the invading
British Army The British Army is the principal Army, land warfare force of the United Kingdom. the British Army comprises 73,847 regular full-time personnel, 4,127 Brigade of Gurkhas, Gurkhas, 25,742 Army Reserve (United Kingdom), volunteer reserve perso ...
. Until the 1940s, the Army was relatively small in peacetime. In 1947, the
Air Force An air force in the broadest sense is the national military branch that primarily conducts aerial warfare. More specifically, it is the branch of a nation's armed services that is responsible for aerial warfare as distinct from an army aviati ...
became completely independent of the Army Air Forces. The Army was under the control of the War Department until 1947, and since then the Defense Department. The U.S. Army fought the Indian Wars of the 1790s, the War of 1812 (1812–15),
Mexican–American War The Mexican–American War (Spanish language, Spanish: ''guerra de Estados Unidos-México, guerra mexicano-estadounidense''), also known in the United States as the Mexican War, and in Mexico as the United States intervention in Mexico, ...
(1846–48),
American Civil War The American Civil War (April 12, 1861May 26, 1865; also known by Names of the American Civil War, other names) was a civil war in the United States between the Union (American Civil War), Union ("the North") and the Confederate States of A ...
(1861–65), American Indian Wars (ended 1890),
Spanish–American War The Spanish–American War (April 21 – August 13, 1898) was fought between Restoration (Spain), Spain and the United States in 1898. It began with the sinking of the USS Maine (1889), USS ''Maine'' in Havana Harbor in Cuba, and resulted in the ...
(1898),
World War I World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...
(1917–18),
World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
(1941–45),
Korean War The Korean War (25 June 1950 – 27 July 1953) was an armed conflict on the Korean Peninsula fought between North Korea (Democratic People's Republic of Korea; DPRK) and South Korea (Republic of Korea; ROK) and their allies. North Korea was s ...
(1950–53) and
Vietnam War The Vietnam War (1 November 1955 – 30 April 1975) was an armed conflict in Vietnam, Laos, and Cambodia fought between North Vietnam (Democratic Republic of Vietnam) and South Vietnam (Republic of Vietnam) and their allies. North Vietnam w ...
(1965–71). Following the
Cold War The Cold War was a period of global Geopolitics, geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which lasted from 1947 unt ...
's end in 1991, Army has focused primarily on
Western Asia West Asia (also called Western Asia or Southwest Asia) is the westernmost region of Asia. As defined by most academics, UN bodies and other institutions, the subregion consists of Anatolia, the Arabian Peninsula, Iran, Mesopotamia, the Armenian ...
, and also took part in the 1991 Gulf War and war in Iraq, and the war in Afghanistan. When the American Revolutionary War began in April 1775, the colonial revolutionaries did not have an army. Previously, each colony had relied upon the
militia A militia ( ) is a military or paramilitary force that comprises civilian members, as opposed to a professional standing army of regular, full-time military personnel. Militias may be raised in times of need to support regular troops or se ...
, made up of part-time civilian-soldiers. The initial orders from Congress authorized ten companies of riflemen. The first full regiment of Regular Army infantry, the 3rd Infantry Regiment, was not formed until June 1784. After the war, the Continental Army was quickly disbanded because of the American distrust of standing armies, and irregular state militias became the new nation's sole ground army, with the exception of a regiment to guard the Western Frontier and one battery of artillery guarding West Point's arsenal. During the War of 1812, an invasion of
Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...
failed due to state militias being widely used, and U.S. troops were unable to stop the British from burning the new capital of Washington, D.C. However, the
Regular Army A regular army is the official army of a state or country (the official armed forces), contrasting with irregular forces, such as volunteer irregular militias, private armies, mercenaries, etc. A regular army usually has the following: * a ...
, under Generals Winfield Scott and Jacob Brown, proved they were professional and capable of winning tactical victories in the Niagara campaign of 1814. Between 1815 and 1860, the main role of the U.S. Army was fighting Native Americans in the West in the American Indian Wars, and manning coast artillery stations at major ports. The U.S. used regular units and many volunteer units in the
Mexican–American War The Mexican–American War (Spanish language, Spanish: ''guerra de Estados Unidos-México, guerra mexicano-estadounidense''), also known in the United States as the Mexican War, and in Mexico as the United States intervention in Mexico, ...
of 1846–48. At the outset of the
American Civil War The American Civil War (April 12, 1861May 26, 1865; also known by Names of the American Civil War, other names) was a civil war in the United States between the Union (American Civil War), Union ("the North") and the Confederate States of A ...
, the regular U.S. Army was small and generally assigned to defend the nation's frontiers from attacks by Indians. Following the Civil War, the U.S. Army fought more wars with Indians, who resisted U.S. expansion into the center of the continent. A combined conscript and volunteer force, the National Army, was formed by the United States War Department in 1917 to fight in
World War I World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...
. During World War II, the Army of the United States was formed as a successor to the National Army. The end of World War II set the stage for the ideological confrontation known as the
Cold War The Cold War was a period of global Geopolitics, geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which lasted from 1947 unt ...
. With the outbreak of the
Korean War The Korean War (25 June 1950 – 27 July 1953) was an armed conflict on the Korean Peninsula fought between North Korea (Democratic People's Republic of Korea; DPRK) and South Korea (Republic of Korea; ROK) and their allies. North Korea was s ...
, concerns over the defense of Western Europe led to the establishment of
NATO The North Atlantic Treaty Organization (NATO ; , OTAN), also called the North Atlantic Alliance, is an intergovernmental organization, intergovernmental Transnationalism, transnational military alliance of 32 Member states of NATO, member s ...
. During the Cold War, American troops and their allies fought communist forces in Korea and
Vietnam Vietnam, officially the Socialist Republic of Vietnam (SRV), is a country at the eastern edge of mainland Southeast Asia, with an area of about and a population of over 100 million, making it the world's List of countries and depende ...
(see containment). The 1980s was mostly a decade of reorganization. The Army converted to an all-volunteer force with greater emphasis on training and technology. By 1989, the Cold War was nearing its conclusion. The Army leadership reacted by starting to plan for a reduction in strength. After Desert Storm, the Army did not see major combat operations for the remainder of the 1990s. After the September 11 attacks, and as part of the War on Terror, U.S. and other NATO forces invaded
Afghanistan Afghanistan, officially the Islamic Emirate of Afghanistan, is a landlocked country located at the crossroads of Central Asia and South Asia. It is bordered by Pakistan to the Durand Line, east and south, Iran to the Afghanistan–Iran borde ...
in 2001, replacing the Taliban government. The Army took part in the U.S. and allied 2003 invasion of Iraq.


Continental Army

The
Continental Army The Continental Army was the army of the United Colonies representing the Thirteen Colonies and later the United States during the American Revolutionary War. It was formed on June 14, 1775, by a resolution passed by the Second Continental Co ...
consisted of troops from all 13 colonies. When the
American Revolutionary War The American Revolutionary War (April 19, 1775 – September 3, 1783), also known as the Revolutionary War or American War of Independence, was the armed conflict that comprised the final eight years of the broader American Revolution, in which Am ...
began at the
Battles of Lexington and Concord The Battles of Lexington and Concord on April 19, 1775 were the first major military actions of the American Revolutionary War between the Kingdom of Great Britain and Patriot (American Revolution), Patriot militias from America's Thirteen Co ...
in April 1775, the revolutionaries in the
Thirteen Colonies The Thirteen Colonies were the British colonies on the Atlantic coast of North America which broke away from the British Crown in the American Revolutionary War (1775–1783), and joined to form the United States of America. The Thirteen C ...
did not have an army. Previously, each colony of
British America British America collectively refers to various British colonization of the Americas, colonies of Kingdom of Great Britain, Great Britain and its predecessors states in the Americas prior to the conclusion of the American Revolutionary War in 1 ...
had relied upon the
militia A militia ( ) is a military or paramilitary force that comprises civilian members, as opposed to a professional standing army of regular, full-time military personnel. Militias may be raised in times of need to support regular troops or se ...
, made up of part-time civilian-soldiers, for local defense, or the raising of temporary "provincial regiments" during specific crises such as the
French and Indian War The French and Indian War, 1754 to 1763, was a colonial conflict in North America between Kingdom of Great Britain, Great Britain and Kingdom of France, France, along with their respective Native Americans in the United States, Native American ...
. As tensions with the British government increased in the years leading up to the war, colonists began to reform their militia in preparation for the potential conflict. Training of militiamen increased after the passage of the Intolerable Acts in 1774. Colonists such as
Richard Henry Lee Richard Henry Lee (January 20, 1732June 19, 1794) was an American statesman and Founding Father from Virginia, best known for the June 1776 Lee Resolution, the motion in the Second Continental Congress calling for the colonies' independence fr ...
proposed creating a national militia force, but the First Continental Congress rejected the idea. On April 23, 1775, the Massachusetts Provincial Congress authorized the raising of a colonial army consisting of 26 company regiments, followed shortly by similar but smaller forces raised by New Hampshire, Rhode Island, and Connecticut. On June 14, 1775, the Second Continental Congress decided to proceed with the establishment of a
Continental Army The Continental Army was the army of the United Colonies representing the Thirteen Colonies and later the United States during the American Revolutionary War. It was formed on June 14, 1775, by a resolution passed by the Second Continental Co ...
for purposes of common defense, adopting the forces already in place outside Boston (22,000 troops) and New York (5,000). It also raised the first ten companies of Continental troops on a one-year enlistment, riflemen from Pennsylvania, Maryland, Delaware and Virginia to be used as
light infantry Light infantry refers to certain types of lightly equipped infantry throughout history. They have a more mobile or fluid function than other types of infantry, such as heavy infantry or line infantry. Historically, light infantry often fought ...
, who later became the 1st Continental Regiment in 1776. On June 15, the Congress elected
George Washington George Washington (, 1799) was a Founding Fathers of the United States, Founding Father and the first president of the United States, serving from 1789 to 1797. As commander of the Continental Army, Washington led Patriot (American Revoluti ...
as Commander-in-Chief by unanimous vote The enlisted soldiers were young, poor, and often of Irish or German background. About one in ten were African American. Washington succeeded in forcing the British out of Boston in 1776, but was defeated and almost captured later that year when he lost New York City. After crossing the Delaware River in the dead of winter, he defeated the British forces in two battles, at Trenton and Princeton, retook New Jersey and restored momentum to the Patriot cause. Because of his strategy, Revolutionary forces captured two major British armies at Saratoga in 1777 and Yorktown in 1781. Historians laud Washington for his selection and supervision of his generals, encouragement of morale and ability to hold together the army, coordination with the state governors and state militia units, relations with Congress and attention to supplies, logistics, intelligence, and training. In battle, however, Washington was repeatedly outmaneuvered by British generals with larger armies. After victory had been achieved in 1783, Washington resigned rather than seize power, proving his opposition to military dictatorship and his commitment to American republicanism.


Organization

The initial orders from Congress authorized ten companies of riflemen. However, the first full regiment of Regular Army infantry, the 3rd Infantry Regiment, was not formed until June 1784. After the authorization of the creation of a Continental Army, Congress, on 16 June 1775, created multiple departments to help support the operations of the Army. These four departments would later be renamed as Corps: the Adjutant General's Corps, the Army Corps of Engineers, the
Finance Corps The United States Army Finance Corps is a combat service support (CSS) branch of the United States Army. The Finance Corps traces its foundation to 16 June 1775, when the Second Continental Congress established the office of Paymaster-General of ...
and the Quartermasters Corps. Congress later authorized both the creation of
Field Artillery Field artillery is a category of mobile artillery used to support army, armies in the field. These weapons are specialized for mobility, tactical proficiency, short range, long range, and extremely long range target engagement. Until the ear ...
and
Cavalry Historically, cavalry (from the French word ''cavalerie'', itself derived from ''cheval'' meaning "horse") are groups of soldiers or warriors who Horses in warfare, fight mounted on horseback. Until the 20th century, cavalry were the most mob ...
units in November 1775 and December 1776 respectively. Broadly speaking, Continental forces consisted of several successive armies, or establishments: * The Continental Army of 1775, comprising the initial
New England New England is a region consisting of six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York (state), New York to the west and by the ...
Army, organized by Washington into three divisions, six brigades, and 38 regiments. Major General
Philip Schuyler Philip John Schuyler (; November 20, 1733 - November 18, 1804) was an American general in the American Revolutionary War, Revolutionary War and a United States Senate, United States Senator from New York (state), New York. He is usually known as ...
's ten regiments in New York were sent to invade
Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...
. * The Continental Army of 1776, reorganized after the initial enlistment period of the soldiers in the 1775 army had expired. Washington had submitted recommendations to the Continental Congress almost immediately after he had accepted the position of Commander-in-Chief, but these took time to consider and implement. Despite attempts to broaden the recruiting base beyond New England, the 1776 army remained skewed toward the Northeast both in terms of its composition and geographical focus. This army consisted of 36 regiments, most standardized to a single battalion of 768 men strong formed into eight companies, with a rank and file strength of 640. * The Continental Army of 1777–80 was a result of several critical reforms and political decisions that came about when it was apparent that the British were sending massive forces to put an end to the
American Revolution The American Revolution (1765–1783) was a colonial rebellion and war of independence in which the Thirteen Colonies broke from British America, British rule to form the United States of America. The revolution culminated in the American ...
. The Continental Congress passed the "Eighty-eight Battalion Resolve", ordering each state to contribute one-battalion regiments in proportion to their population, and Washington was subsequently given authority to raise an additional 16 battalions. Also, enlistment terms were extended to three years or "the length of the war" to avoid the year-end crises that depleted forces (including the notable near collapse of the army at the end of 1776 which could have ended the war in a Continental, or American, loss by forfeit). * The Continental Army of 1781–82 saw the greatest crisis on the American side in the war. Congress was bankrupt, making it very difficult to replenish the soldiers whose three-year terms had expired. Popular support for the war was at its all-time low, and Washington had to put down mutinies both in the Pennsylvania Line and New Jersey Line. Congress voted to cut funding for the Army, but Washington managed nevertheless to secure important strategic victories. * The Continental Army of 1783–84 was succeeded by the
United States Army The United States Army (USA) is the primary Land warfare, land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of th ...
, which persists to this day. As peace was closed with the British, most of the regiments were disbanded in an orderly fashion, though several had already been diminished. In addition to the Continental Army regulars, local militia units, raised and funded by individual colonies/states, participated in battles throughout the war. Sometimes, the militia units operated independently of the Continental Army, but often local militias were called out to support and augment the Continental Army regulars during campaigns. (The militia troops developed a reputation for being prone to premature retreats, a fact that was integrated into the strategy at the
Battle of Cowpens The Battle of Cowpens was a military engagement during the American Revolutionary War fought on January 17, 1781, near the town of Cowpens, South Carolina. American Patriot (American Revolution), Patriot forces, estimated at 2,000 militia and reg ...
.)


Early national period (1783–1812)

In 1783, at the conclusion of the Revolutionary War, a Congressional committee under
Alexander Hamilton Alexander Hamilton (January 11, 1755 or 1757July 12, 1804) was an American military officer, statesman, and Founding Fathers of the United States, Founding Father who served as the first U.S. secretary of the treasury from 1789 to 1795 dur ...
sought opinions on a permanent armed force. Washington submitted his "Sentiments on a Peace Establishment," which called for only a small force of only 2,631 men regiment to guard the western frontier and the borders with Canada and Florida. Planning for the transition to a peacetime force had begun in April 1783 at the request of a congressional committee chaired by
Alexander Hamilton Alexander Hamilton (January 11, 1755 or 1757July 12, 1804) was an American military officer, statesman, and Founding Fathers of the United States, Founding Father who served as the first U.S. secretary of the treasury from 1789 to 1795 dur ...
. The commander-in-chief discussed the problem with key officers before submitting the army's official views on May 2. Significantly, there was a broad consensus on the basic framework among the officers. Washington's proposal called for four components: a small regular army, a uniformly trained and organized militia, a system of arsenals, and a military academy to train the army's artillery and engineer officers. He wanted four infantry regiments, each assigned to a specific sector of the frontier, plus an artillery regiment. His proposed regimental organizations followed Continental Army patterns but had a provision for increased strength in the event of war. Washington expected the militia primarily to provide security for the country at the start of a war until the regular army could expand—the same role it had carried out in 1775 and 1776. Steuben and Duportail submitted their own proposals to Congress for consideration. Congress again rejected Washington's concept for a peacetime force in October 1783. When moderate delegates then offered an alternative in April 1784 which scaled the projected army down to 900 men in one artillery and three infantry battalions, Congress rejected it as well, in part because New York feared that men retained from Massachusetts might take sides in a land dispute between Vermont and New York. Another proposal to retain 350 men and raise 700 new recruits also failed. On June 2, Congress ordered the discharge of all remaining men except twenty-five caretakers at Fort Pitt and fifty-five at West Point. The next day it created a peace establishment acceptable to all interests. The plan required four states to raise 700 men for one year's service. Congress instructed the Secretary of War to form the troops into eight infantry and two artillery companies. Pennsylvania, with a quota of 260 men, had the power to nominate a lieutenant colonel, who would be the senior officer. New York and Connecticut each were to raise 165 men and nominate a major; the remaining 110 men came from New Jersey. The economy was the watchword of this proposal, for each major served as a company commander, and line officers performed all staff duties except those of chaplain, surgeon, and surgeon's mate. Under Josiah Harmar, the First American Regiment slowly organized and achieved permanent status as an infantry regiment of the new Regular Army. The lineage of the First American Regiment is carried on by the 3rd United States Infantry Regiment (The Old Guard) Economic constraints forced the new nation to rely heavily on irregular state militias. The Continental Army was quickly disbanded as part of the American distrust of standing armies, with the exception of the First American Regiment to guard the Western Frontier and one battery of artillery guarding West Point's arsenal. However, because of continuing conflict with Indians, it was soon realized that it was necessary to field a trained standing army. The first of these, the Legion of the United States, was established between June and November 1792 at Fort Lafayette, Pennsylvania, under Major Gen. "Mad" Anthony Wayne. The newly formed Legion moved in December 1792 to an encampment downriver on the
Ohio River The Ohio River () is a river in the United States. It is located at the boundary of the Midwestern and Southern United States, flowing in a southwesterly direction from Pittsburgh, Pennsylvania, to its river mouth, mouth on the Mississippi Riv ...
near Fort McIntosh named Legionville for training. In September 1793, the Legion moved by barge down the Ohio to a camp named Hobson's Choice two miles from Fort Washington (
Cincinnati Cincinnati ( ; colloquially nicknamed Cincy) is a city in Hamilton County, Ohio, United States, and its county seat. Settled in 1788, the city is located on the northern side of the confluence of the Licking River (Kentucky), Licking and Ohio Ri ...
) on the western frontier. There it was joined by units from the Kentucky Militia. Their assignment was to advance to the site of St. Clair's earlier defeat, recover the cannons lost there, and continue to the Miami capital at Kekionga to establish U.S. sovereignty over northern and western Ohio and beyond. However, the United States military realized it needed a well-trained standing army following St. Clair's defeat on November 4, 1791, when a force led by Major General Arthur St. Clair was almost entirely wiped out by the Northwestern Confederacy near Fort Recovery, Ohio. The plans, which were supported by U.S. President George Washington and Henry Knox, Secretary of War, led to the disbandment of the Continental Army and the creation of the Legion of the United States. The command would be based on the 18th-century military works of Henry Bouquet, a professional Swiss soldier who served as a
colonel Colonel ( ; abbreviated as Col., Col, or COL) is a senior military Officer (armed forces), officer rank used in many countries. It is also used in some police forces and paramilitary organizations. In the 17th, 18th, and 19th centuries, a colon ...
in the
British Army The British Army is the principal Army, land warfare force of the United Kingdom. the British Army comprises 73,847 regular full-time personnel, 4,127 Brigade of Gurkhas, Gurkhas, 25,742 Army Reserve (United Kingdom), volunteer reserve perso ...
, and French
Marshal Marshal is a term used in several official titles in various branches of society. As marshals became trusted members of the courts of Middle Ages, Medieval Europe, the title grew in reputation. During the last few centuries, it has been used fo ...
Maurice de Saxe. In 1792, Anthony Wayne, a renowned hero of the American Revolutionary War, was encouraged to leave retirement and return to active service as Commander-in-Chief of the Legion with the rank of major general. A month later, the combined force under Wayne and Brigadier General Scott of Kentucky advanced northward into Indian territory beyond the northern outpost Fort Jefferson to establish the first in a succession of frontier forts on Ohio's western border named Fort Greene Ville. The northern campaign culminated in victory at the Battle of Fallen Timbers in August 1794 near what is today the city of
Toledo, Ohio Toledo ( ) is a city in Lucas County, Ohio, United States, and its county seat. It is located at the western end of Lake Erie along the Maumee River. Toledo is the List of cities in Ohio, fourth-most populous city in Ohio and List of United Sta ...
, near the Ohio/Michigan border. The legion then advanced unopposed to Kekionga in northern Indiana near the Ohio border and established Fort Wayne at the site of the future city. The Treaty of Greenville in 1795 brought peace to the northern Ohio frontier and opened eastern and southern Ohio to settlement. The legion established other forts after
Fort Wayne Fort Wayne is a city in Allen County, Indiana, United States, and its county seat. Located in northeastern Indiana, the city is west of the Ohio border and south of the Michigan border. The city's population was 263,886 at the 2020 United S ...
, notably Fort St. Mary's in western Ohio, and the settlement that grew up there was the site of several significant treaties in 1818. After Wayne's death in 1796, command of the legion passed to Wayne's executive officer and commandant of Fort Washington, Brig. Gen. James Wilkinson. The Legion was renamed the United States Army. The Legion was recruited and raised in
Pittsburgh Pittsburgh ( ) is a city in Allegheny County, Pennsylvania, United States, and its county seat. It is the List of municipalities in Pennsylvania#Municipalities, second-most populous city in Pennsylvania (after Philadelphia) and the List of Un ...
. It was formed into four sub-legions. These were created from elements of the 1st and 2nd Regiments from the Continental Army. These units then became the First and Second Sub-Legions. The Third and Fourth Sub-Legions were raised from further recruits. From June 1792 to November 1792, the Legion was stationed at Fort LaFayette in Pittsburgh. Throughout the winter of 1792-3, existing troops along with new recruits were drilled in military skills, tactics, and discipline at Legionville on the banks of the
Ohio River The Ohio River () is a river in the United States. It is located at the boundary of the Midwestern and Southern United States, flowing in a southwesterly direction from Pittsburgh, Pennsylvania, to its river mouth, mouth on the Mississippi Riv ...
near present-day Baden, Pennsylvania. The following Spring the newly named Legion of the United States left Legionville for the Northwest Indian War, a struggle between American Indian tribes affiliated with the Northwestern Confederacy in the area south of the
Ohio River The Ohio River () is a river in the United States. It is located at the boundary of the Midwestern and Southern United States, flowing in a southwesterly direction from Pittsburgh, Pennsylvania, to its river mouth, mouth on the Mississippi Riv ...
. The overwhelmingly successful campaign was concluded with the decisive victory at Fallen Timbers on August 20, 1794, Major General Anthony Wayne applied the techniques of wilderness operations perfected by Sullivan's 1779 expedition against the Iroquois. The training the troops received at Legionville was also seen as instrumental to this overwhelming victory. Nevertheless, Steuben's Blue Book remained the official manual for the legion, as well as for the militia of most states, until Winfield Scott in 1835. In 1796, the United States Army was raised following the discontinuation of the legion of the United States. In 1798, during the  Quasi-War with France, the U.S. Congress established a three-year " Provisional Army" of 10,000 men, consisting of twelve regiments of infantry and six troops of light dragoons.


19th century


War of 1812

The War of 1812, the second and last American war against the British, was less successful than the Revolution had been. An invasion of Canada failed due to the over-reliance of using state militias, and U.S. troops were unable to stop the
British Army The British Army is the principal Army, land warfare force of the United Kingdom. the British Army comprises 73,847 regular full-time personnel, 4,127 Brigade of Gurkhas, Gurkhas, 25,742 Army Reserve (United Kingdom), volunteer reserve perso ...
from burning the new capital of Washington, D.C. However, the Regular Army, under Generals Winfield Scott and Jacob Brown, proved they were professional and able to win tactical victories in the Niagara campaign of 1814. The nation celebrated the Southern militia's great victory under
Andrew Jackson Andrew Jackson (March 15, 1767 – June 8, 1845) was the seventh president of the United States from 1829 to 1837. Before Presidency of Andrew Jackson, his presidency, he rose to fame as a general in the U.S. Army and served in both houses ...
, at the Battle of New Orleans in January 1815, after the war had ended with the signing of the Treaty of Ghent on 24 December 1814. The multiple failures and fiascos of the War of 1812 showed that thorough reform of the War Department was necessary. Secretary of War John C. Calhoun reorganized the department into a system of bureaus, whose chiefs held office for life, and a commanding general in the field, although the Congress did not authorize this position. Through the 1840s and 1850s, Winfield Scott was the senior general, only retiring at the start of the
American Civil War The American Civil War (April 12, 1861May 26, 1865; also known by Names of the American Civil War, other names) was a civil war in the United States between the Union (American Civil War), Union ("the North") and the Confederate States of A ...
in 1861. The bureau chiefs acted as advisers to the Secretary of War while commanding their own troops and field installations. The bureaus frequently conflicted among themselves, but in disputes with the commanding general, the Secretary of War generally supported the bureaus. Congress regulated the affairs of the bureaus in detail, and their chiefs looked to that body for support. Calhoun set up the
Bureau of Indian Affairs The Bureau of Indian Affairs (BIA), also known as Indian Affairs (IA), is a United States List of United States federal agencies, federal agency within the U.S. Department of the Interior, Department of the Interior. It is responsible for im ...
in 1824, the main agency within the War Department for dealing with Native Americans until 1849, when the Congress transferred it to the newly founded
Department of the Interior The United States Department of the Interior (DOI) is an executive department of the U.S. federal government responsible for the management and conservation of most federal lands and natural resources. It also administers programs relatin ...
.


Westward Expansion

Between 1815 and 1860, the main role of the Army was control of Indians in the West, and manning coast artillery stations at major ports. Most of the forces were stationed on the frontier, or and coastal defense units near seaports. Transportation was a key issue and the Army (especially the Army Corps of Engineers) was given full responsibility for facilitating navigation on the rivers. The steamboat, first used on the Ohio River in 1811, made possible inexpensive travel using the river systems, especially the Mississippi and Missouri rivers and their tributaries. Army expeditions up the
Missouri River The Missouri River is a river in the Central United States, Central and Mountain states, Mountain West regions of the United States. The nation's longest, it rises in the eastern Centennial Mountains of the Bitterroot Range of the Rocky Moun ...
in 1818–25 allowed engineers to improve the technology. For example, the Army's steamboat " Western Engineer" of 1819 combined a very shallow draft with one of the earliest stern wheels. In 1819–25 Colonel Henry Atkinson developed keelboats with hand-powered paddle wheels.


Seminole Wars

As the United States expanded westward, it also aimed to expand into Florida, both as a means to protect its southern border as well as to cut off an escape route for runaway slaves. This campaign resulted in the Seminole Wars in Florida. The First Seminole War was from 1814 to 1819, the Second Seminole War from 1835 to 1842, and the Third Seminole War from 1855 to 1858. While the majority of the Seminole ended up moving west onto reservations, some remained in
Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...
.


War with Mexico

The U.S. used regular units and many volunteer units to fight Mexico, 1846–48. The American strategy was threefold: to take control of the Southwest (New Mexico and California); to invade Mexico from the North under general Zachary Taylor. Finally to land troops and capture Mexico City with an army under General Winfield Scott. All the operations were successful; the Americans won all the major battles. The army expanded from 6,000 regulars to more than 115,000. Of these, approximately 1.5% were killed in the fighting and nearly 10% died of disease; another 12% were wounded or discharged because of disease.


Civil War

At the outset of the
American Civil War The American Civil War (April 12, 1861May 26, 1865; also known by Names of the American Civil War, other names) was a civil war in the United States between the Union (American Civil War), Union ("the North") and the Confederate States of A ...
the regular U.S. army was small and generally assigned to defend the nation's frontiers from Indian attacks. As one after another Southern state seceded many experienced officers and men resigned or left to join the
Confederate States Army The Confederate States Army (CSA), also called the Confederate army or the Southern army, was the Military forces of the Confederate States, military land force of the Confederate States of America (commonly referred to as the Confederacy) duri ...
, further limiting the regular army's abilities. The attack on
Fort Sumter Fort Sumter is a historical Coastal defense and fortification#Sea forts, sea fort located near Charleston, South Carolina. Constructed on an artificial island at the entrance of Charleston Harbor in 1829, the fort was built in response to the W ...
by South Carolina militia marked the beginning of hostilities. Both sides recruited large numbers of men into a new Volunteer Army, recruited and formed by the states. Regiments were recruited locally, with company officers elected by the men. Although many officers in the regular army accepted commissions in the new volunteer units outsiders were not usually welcome as officers, unless they were surgeons whose value was obvious. Colonels – often local politicians who helped raise the troops – were appointed by the governors, and generals were appointed by President
Abraham Lincoln Abraham Lincoln (February 12, 1809 – April 15, 1865) was the 16th president of the United States, serving from 1861 until Assassination of Abraham Lincoln, his assassination in 1865. He led the United States through the American Civil War ...
. The Volunteer Army was so much larger than the Regular Army that entirely new units above the regimental level had to be formed. The grand plan involved geographical theaters, with armies (named after rivers such as the Army of the Potomac in the Eastern Theater) comprising brigades, divisions and corps headquarters. The rapidly growing armies were relatively poorly trained when the first major battle of the war occurred at Bull Run in the middle of 1861. The embarrassing Union defeat and subsequent inability of the Confederacy to capitalize on their victory resulted in both sides spending more time organizing and training their green armies. Much of the subsequent actions taken in 1861 were skirmishes between pro-Union and pro-Confederacy irregular forces in border states like Missouri and Kentucky. In 1862 the war became much more bloody, though neither side was able to gain a lasting strategic advantage over the other. However, the decisive battles of Gettysburg in the east and Vicksburg in the west allowed the momentum of the war to shift in favor of the Union in 1863. Increasingly, Confederate forces were outmatched by the more numerous and better equipped Union forces, whose greater population and economic resources became critical factors as the war became one of attrition. An increasingly effective naval blockade further damaged the Confederate war economy. By 1864, long-term Union advantages in geography, manpower, industry, finance, political organization and transportation were overwhelming the Confederacy. Grant fought a remarkable series of bloody battles with Lee in Virginia in the summer of 1864. Lee's defensive tactics resulted in higher casualties for Grant's army, but Lee lost strategically overall as he could not replace his casualties and was forced to retreat into trenches around his capital,
Richmond, Virginia Richmond ( ) is the List of capitals in the United States, capital city of the Commonwealth (U.S. state), U.S. commonwealth of Virginia. Incorporated in 1742, Richmond has been an independent city (United States), independent city since 1871. ...
. Meanwhile, in the West,
William Tecumseh Sherman William Tecumseh Sherman ( ; February 8, 1820February 14, 1891) was an American soldier, businessman, educator, and author. He served as a General officer, general in the Union Army during the American Civil War (1861–1865), earning recognit ...
captured Atlanta in 1864. His March to the Sea destroyed a hundred-mile-wide swath of Georgia, with little Confederate resistance. In 1865, the Confederacy collapsed after Lee surrendered to Grant at Appomattox Courthouse. In all, 2.2 million men served in the Union army; 360,000 of whom died from all causes – two-thirds from disease. The Volunteer Army was demobilized in summer 1865.


Logistics

While the Confederacy suffered from a worsening lack of adequate supplies, the Union forces typically had enough food, supplies, ammunition and weapons. The Union supply system, even as it penetrated deeper into the South, maintained its efficiency. The key leader was Quartermaster General Montgomery C. Meigs. Union quartermasters were responsible for most of the $3 billion spent for the war. They operated out of sixteen major depots, which formed the basis of the system of procurement and supply throughout the war. As the war expanded, operation of these depots became much more complex, with an overlapping and interweaving relationship between the Army and government operated factories, private factories, and numerous middlemen. The purchase of goods and services through contracts supervised by the quartermasters accounted for most of federal military expenditures, apart from the wages of the soldiers. The quartermasters supervised their own soldiers, and cooperated closely with state officials, manufacturers and wholesalers trying to sell directly to the army; and representatives of civilian workers looking for higher pay at government factories. The complex system was closely monitored by congressmen anxious to ensure that their districts won their share of contracts.


Black soldiers

Lincoln's Emancipation Proclamation of January 1, 1863, enabled both free blacks and escaped slaves, to join the Union Army. About 190,000 volunteered, further enhancing the numerical advantage the Union armies enjoyed over the Confederates, who did not dare emulate the equivalent manpower source for fear of fundamentally undermining the legitimacy of slavery. Black Union soldiers were mostly used in garrison duty, but they fought in several battles, such as the Battle of the Crater (1864), and the Battle of Nashville (1865). There was bad blood between Confederates and black soldiers, with no quarter given by the Confederates. At Ft. Pillow on April 12, 1864 Confederate units under Maj. Gen. Nathan Bedford Forrest went wild and massacred black soldiers attempting to surrender, which further inflamed passions.


Indian wars of the late 19th century

Following the Civil War, the U.S. Army fought a series of wars with Native Americans, who resisted U.S. expansion into the center of the continent. By the 1890s the U.S. saw itself as a potential international player. The Army played a central role in winning the
Spanish–American War The Spanish–American War (April 21 – August 13, 1898) was fought between Restoration (Spain), Spain and the United States in 1898. It began with the sinking of the USS Maine (1889), USS ''Maine'' in Havana Harbor in Cuba, and resulted in the ...
of 1898 and the less well known
Philippine–American War The Philippine–American War, known alternatively as the Philippine Insurrection, Filipino–American War, or Tagalog Insurgency, emerged following the conclusion of the Spanish–American War in December 1898 when the United States annexed th ...
of 1899–1901. As settlement sped up across the West after the transcontinental railroad was completed in 1869, clashes with Native Americans of the Plains and southwest reached a final phase. The military's mission was to clear the land of free-roaming Indians and put them onto reservations. The stiff resistance of battle-hardened, well-armed mounted Indian warriors resulted in the Indian Wars. In the Apache and Navajo Wars, Colonel Christopher "Kit" Carson forced the Mescalero Apache onto a reservation in 1862. Skirmishes between Americans and Apaches continued until after the turn of the century. In 1863–1864, Carson used a scorched earth policy in the ''Navajo campaign'', burning Navajo fields and homes, and capturing or killing their livestock. He was aided by other Indian tribes with long-standing enmity toward the Navajos, chiefly the Utes. Later in 1864, he fought a combined force of more than one thousand Kiowa, Comanche, and Plains Apache at the First Battle of Adobe Walls. Carson retreated but he managed to destroy an Indian village and winter supplies. In the Red River War which followed the U.S. army systematically destroyed Comanche property, horses, and livelihood in the Texas panhandle, resulting in the surrender of the last Comanche war chief, Quanah Parker, in June 1875. In June 1877, in the Nez Perce War the Nez Perce under Chief Joseph, unwilling to give up their traditional lands and move to a reservation, undertook a 1,200 mile fighting retreat from
Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...
to near the Canada–US border in
Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...
. Numbering only 200 warriors, the Nez Perce battled some 2,000 American regulars and volunteers in a total of eighteen engagements, including four major battles and at least four fiercely contested skirmishes." The Nez Perce were finally surrounded at the Battle of Bear Paw and surrendered. The Great Sioux War of 1876–77 was conducted by the Lakota under Sitting Bull and
Crazy Horse Crazy Horse ( , ; – September 5, 1877) was a Lakota people, Lakota war leader of the Oglala band. He took up arms against the United States federal government to fight against encroachment by White Americans, White American settlers on Nativ ...
. The conflict began after repeated violations of the Treaty of Fort Laramie (1868) once gold was discovered in the hills. By far the most famous battle was the one-sided Indian victory at the
Battle of the Little Bighorn The Battle of the Little Bighorn, known to the Lakota people, Lakota and other Plains Indians as the Battle of the Greasy Grass, and commonly referred to as Custer's Last Stand, was an armed engagement between combined forces of the Lakota Si ...
, in which combined Sioux and Cheyenne forces defeated the 7th Cavalry, led by General George Armstrong Custer. The West was largely pacified by 1890, apart from small Indian raids along the Mexican border. Combat in the Indian wars resulted in the deaths of about 4,340 people, including soldiers, civilians and Native Americans. In all the Indian wars combined from 1790 to 1910, regular cavalry units fought in about 1000 engagements and suffered more than 2000 total killed and wounded. Disease and accidents caused far more Army casualties than combat; annually, eight soldiers per 1000 died from disease, and five per 1000 died from battle wounds or accidents.


Spanish–American and Philippine–American Wars


Twentieth century


Chief of Staff

Elihu Root was United States Secretary of War under presidents
William McKinley William McKinley (January 29, 1843September 14, 1901) was the 25th president of the United States, serving from 1897 until Assassination of William McKinley, his assassination in 1901. A member of the Republican Party (United States), Repub ...
and
Theodore Roosevelt Theodore Roosevelt Jr. (October 27, 1858 – January 6, 1919), also known as Teddy or T.R., was the 26th president of the United States, serving from 1901 to 1909. Roosevelt previously was involved in New York (state), New York politics, incl ...
, 1899–1904. He reformed the organization of the War Department. He enlarged West Point and established the
U.S. Army War College The United States Army War College (USAWC) is a United States Army, U.S. Army staff college in Carlisle Barracks, Pennsylvania, with a Carlisle, Pennsylvania, Carlisle postal address, on the 500-acre (2 km2) campus of the historic Carlisle B ...
, as well as the
General Staff A military staff or general staff (also referred to as army staff, navy staff, or air staff within the individual services) is a group of officers, Enlisted rank, enlisted, and civilian staff who serve the commanding officer, commander of a ...
. He changed the procedures for promotions and organized schools for the special branches of the service. He also devised the principle of rotating officers from staff to line. General Samuel Baldwin Marks Young became the first chief of staff in 1903-1904. The headquarters moved to Fort Myer in 1908. According to Louis Cantor, Root designed a dual role for the
National Guard National guard is the name used by a wide variety of current and historical uniformed organizations in different countries. The original National Guard was formed during the French Revolution around a cadre of defectors from the French Guards. ...
- a militia for state service and a trained reserve for the regular army. Congress enacted this system embodied in the Dick Act (1903). Prior to 1903, the senior military officer in the army was the Commanding General of the United States Army, who reported to the Secretary of War. From 1864 to 1865, Major General
Henry Halleck Henry Wager Halleck (January 16, 1815 – January 9, 1872) was a senior United States Army officer, scholar, and lawyer. A noted expert in military studies, he was known by a nickname that became derogatory: "Old Brains". He was an important part ...
(who had previously been Commanding General) served as "Chief of Staff of the Army" under the Commanding General, Lieutenant General Ulysses S. Grant, thus serving in a different office and not as the senior officer in the army.


Reorganization

In 1910, the U.S. Signal Corps acquired and flew the Army's first aircraft, the Wright Model A biplane. The Maneuver Division was formed in
San Antonio, Texas San Antonio ( ; Spanish for "Anthony of Padua, Saint Anthony") is a city in the U.S. state of Texas and the most populous city in Greater San Antonio. San Antonio is the List of Texas metropolitan areas, third-largest metropolitan area in Texa ...
, in March 1911, to undertake offensive operations against Mexico during the
Mexican Revolution The Mexican Revolution () was an extended sequence of armed regional conflicts in Mexico from 20 November 1910 to 1 December 1920. It has been called "the defining event of modern Mexican history". It saw the destruction of the Federal Army, its ...
. This was the United States' first attempt at modernizing the division concept. Major General Leonard Wood, then Army Chief of Staff, mobilized the division primarily to demonstrate to Congress that the United States was not adequately prepared for modern warfare. The division was disbanded on 7 August 1911. Because of the mobilization difficulties experienced with the Maneuver Division, on 15 February 1913 a standing organization of a "regular army organized in divisions and cavalry brigades ready for immediate use as an expeditionary force or for other purposes..." and "an army of national citizen soldiers organized in peace in complete divisions and prepared to reenforce the Regular Army in time of war" was organized by Secretary of War Henry L. Stimson and known as the "Stimson Plan." The
contiguous United States The contiguous United States, also known as the U.S. mainland, officially referred to as the conterminous United States, consists of the 48 adjoining U.S. states and the District of Columbia of the United States in central North America. The te ...
was divided into four geographic departments ( Eastern, Central, Western, and Southern) and a regular army division assigned to each, and 12 geographic districts, each with a national guard infantry division assigned. 32 of the 48 state governors committed their national guards to support of the plan. There were also three artillery commands: the Northern Atlantic Coast Artillery District, the Southern Atlantic Coast Artillery District, and the Pacific Coast Artillery District. In 1914 and 1916, U.S. troops were sent into Mexico during the
Mexican Revolution The Mexican Revolution () was an extended sequence of armed regional conflicts in Mexico from 20 November 1910 to 1 December 1920. It has been called "the defining event of modern Mexican history". It saw the destruction of the Federal Army, its ...
. The Pancho Villa Expedition under Brigadier General John J. Pershing attempted to capture
Pancho Villa Francisco "Pancho" Villa ( , , ; born José Doroteo Arango Arámbula; 5 June 1878 – 20 July 1923) was a Mexican revolutionary and prominent figure in the Mexican Revolution. He was a key figure in the revolutionary movement that forced ...
, a Mexican who had mounted attacks on U.S. border towns. The skirmishes on the border later became known as the Border War (1910–19).


World War I

A combined conscript and volunteer force, the National Army, was formed by the United States War Department in 1917 to fight in
World War I World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...
. The National Army was formed from the old core of the regular
United States Army The United States Army (USA) is the primary Land warfare, land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of th ...
, augmented by units of the
United States National Guard The National Guard is a U.S. state, state-based military force that becomes part of the United States Armed Forces, U.S. military's reserve components of the United States Armed Forces, reserve components of the United States Army, U.S. Army a ...
and a large
draft Draft, the draft, or draught may refer to: Watercraft dimensions * Draft (hull), the distance from waterline to keel of a vessel * Draft (sail), degree of curvature in a sail * Air draft, distance from waterline to the highest point on a v ...
of able-bodied men. Moral standards, and the morale of the troops, was the concern of the Commission on Training Camp Activities. The Selective Service Act of 1917 established the broad outlines of the Army's structure. There were to be three increments: # The Regular Army, to be raised immediately to the full wartime strength of 286,000 authorized in the National Defense Act of 1916; # The National Guard, also to be expanded immediately to the authorized strength of approximately 450,000; and # A National Army (the National Defense Act had called it a Volunteer Army), to be created in two increments of 500,000 men each at such time as the President should determine. Much of the identity of these three segments eventually would be lost as recruits and draftees alike were absorbed in all units, so that in mid-1918 the War Department would change the designation of all land forces to one "United States Army." The original segment to which regiments, brigades, and divisions belonged nevertheless remained apparent from numerical designations. For the Regular Army, for example, divisions were numbered up to 25, while numbers 26 through 49 were reserved for the National Guard and 50 through higher numbers for divisions of the National Army. At its greatest size the National Army had more than six million men, two million of whom fought on the western front. Promotions within the National Army were quick, with most United States Army officers receiving double and triple promotions within a space of only two years. For example, Dwight D. Eisenhower entered the National Army as a captain and was a lieutenant colonel one year later. Douglas MacArthur also advanced quickly in the National Army, rising from major to brigadier general in two years. The Army entered
World War I World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...
with very large divisions, often numbering more than 30,000 men (the 4th Division contained 32,000, for example) and consisting of two infantry brigades of two regiments each, with a total of sixteen infantry battalions per division. Each division also had three artillery regiments and an engineer regiment. The United States joined World War I in April 1917. Because of the necessary period of training before the units were moved overseas, the first elements of the American Expeditionary Forces arrived in June 1917. Their first actions of the Western Front came in October 1917. U.S. troops contributed to the offensive that finally broke through the German lines. With the
armistice An armistice is a formal agreement of warring parties to stop fighting. It is not necessarily the end of a war, as it may constitute only a cessation of hostilities while an attempt is made to negotiate a lasting peace. It is derived from t ...
on 11 November 1918, the Army once again decreased its forces.


Interwar period

The National Army was disbanded in 1920 and all personnel not subject to demobilization who had held ranks in the National Army were reverted to
Regular Army A regular army is the official army of a state or country (the official armed forces), contrasting with irregular forces, such as volunteer irregular militias, private armies, mercenaries, etc. A regular army usually has the following: * a ...
status. George S. Patton, who had been a
colonel Colonel ( ; abbreviated as Col., Col, or COL) is a senior military Officer (armed forces), officer rank used in many countries. It is also used in some police forces and paramilitary organizations. In the 17th, 18th, and 19th centuries, a colon ...
in the National Army, returned to the Regular Army as a captain. Some, such as Douglas MacArthur, maintained their wartime rank in the Regular Army. For those keeping their wartime ranks the reality was, however, that they would usually remain at that specific rank for years. This often resulted in talented officers leaving service in the interwar years. After establishing post-World War I divisions, the Army experienced a prolonged period of stagnation and deterioration. The National Defense Act of 1920 authorized a Regular Army of 296,000 men, but Congress gradually backed away from that number. As with the Regular Army, the
National Guard National guard is the name used by a wide variety of current and historical uniformed organizations in different countries. The original National Guard was formed during the French Revolution around a cadre of defectors from the French Guards. ...
never recruited its authorized 486,000 men, and the Organized Reserves became merely a pool of reserve officers. The root of the Army's problem was money. Congress yearly appropriated only about half the funds that the General Staff requested. Impoverished in manpower and funds, infantry and cavalry divisions dwindled to skeletal organizations. Between 1923 and 1939 divisions gradually declined as fighting organizations. After Regular Army divisions moved to permanent posts, the War Department modified command relationships between divisional units and the corps areas, making division and brigade commanders responsible only for unit training. They were limited to two visits per year to their assigned elements – and that only if corps area commanders made funds available. Later, as a further economy move, the War Department reduced the number of command visits to one per year,


World War II

During
World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
, the Army of the United States was formed as a successor to the National Army. The Army of the United States operated on the same principles as its predecessor, combining
Regular Army A regular army is the official army of a state or country (the official armed forces), contrasting with irregular forces, such as volunteer irregular militias, private armies, mercenaries, etc. A regular army usually has the following: * a ...
,
National Guard National guard is the name used by a wide variety of current and historical uniformed organizations in different countries. The original National Guard was formed during the French Revolution around a cadre of defectors from the French Guards. ...
, and conscript forces into one fighting unit. The Army of the United States also incorporated Reserve forces. The reorganized army doubled in size between the
invasion of Poland The invasion of Poland, also known as the September Campaign, Polish Campaign, and Polish Defensive War of 1939 (1 September – 6 October 1939), was a joint attack on the Second Polish Republic, Republic of Poland by Nazi Germany, the Slovak R ...
and the
attack on Pearl Harbor The attack on Pearl HarborAlso known as the Battle of Pearl Harbor was a surprise military strike by the Empire of Japan on the United States Pacific Fleet at Naval Station Pearl Harbor, its naval base at Pearl Harbor on Oahu, Territory of ...
, and grew forty-four times between the US entry into the war and the
surrender of Japan The surrender of the Empire of Japan in World War II was Hirohito surrender broadcast, announced by Emperor Hirohito on 15 August and formally Japanese Instrument of Surrender, signed on 2 September 1945, End of World War II in Asia, ending ...
. The United States entered World War II after the Japanese
attack on Pearl Harbor The attack on Pearl HarborAlso known as the Battle of Pearl Harbor was a surprise military strike by the Empire of Japan on the United States Pacific Fleet at Naval Station Pearl Harbor, its naval base at Pearl Harbor on Oahu, Territory of ...
in December 1941. The U.S. Army fought World War II with more flexible divisions, consisting of three infantry regiments of three infantry battalions each. Most soldiers' time was spent in training in the United States, with large numbers only going overseas in 1944. In the
Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the cont ...
, Army soldiers participated alongside the U.S. Marine Corps in the " island hopping" campaign that wrested the
Pacific Islands The Pacific islands are a group of islands in the Pacific Ocean. They are further categorized into three major island groups: Melanesia, Micronesia, and Polynesia. Depending on the context, the term ''Pacific Islands'' may refer to one of several ...
from Japanese control. On the European front, U.S. Army troops formed a significant portion of the forces that captured
North Africa North Africa (sometimes Northern Africa) is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region. However, it is sometimes defined as stretching from the Atlantic shores of t ...
and
Sicily Sicily (Italian language, Italian and ), officially the Sicilian Region (), is an island in the central Mediterranean Sea, south of the Italian Peninsula in continental Europe and is one of the 20 regions of Italy, regions of Italy. With 4. ...
and later fought in Italy. On D-Day, 6 June 1944, and in the subsequent liberation of Europe and defeat of
Nazi Germany Nazi Germany, officially known as the German Reich and later the Greater German Reich, was the German Reich, German state between 1933 and 1945, when Adolf Hitler and the Nazi Party controlled the country, transforming it into a Totalit ...
, millions of U.S. Army troops played a central role. Following the Axis surrenders in May (Germany) and August (Japan) of 1945, Army troops were deployed in Germany and to Japan to occupy the two defeated nations. The
United States Army Air Forces The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II ...
, which was an outgrowth of the earlier Army Air Corps, had been virtually independent during the war. In 1947, it separated from the Army to become the
United States Air Force The United States Air Force (USAF) is the Air force, air service branch of the United States Department of Defense. It is one of the six United States Armed Forces and one of the eight uniformed services of the United States. Tracing its ori ...
. Shortly after the war, in 1948, the Women's Armed Services Integration Act gave women permanent status in the Regular and Reserve forces of the Army.


Cold War

The end of World War II set the stage for the East-West confrontation known as the
Cold War The Cold War was a period of global Geopolitics, geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which lasted from 1947 unt ...
, which lasted for the next 45 years. With the outbreak of the
Korean War The Korean War (25 June 1950 – 27 July 1953) was an armed conflict on the Korean Peninsula fought between North Korea (Democratic People's Republic of Korea; DPRK) and South Korea (Republic of Korea; ROK) and their allies. North Korea was s ...
, concerns over the defense of Western Europe rose. Two corps, V and VII, were reactivated under Seventh United States Army in 1950 and American strength in Europe rose from one division to four. Hundreds of thousands of U.S. troops remained stationed in West Germany, with others in Belgium, the Netherlands and the United Kingdom, until the 1990s in anticipation of a possible
Soviet The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...
attack. During the Cold War, American troops and their allies fought Communist forces in Korea and
Vietnam Vietnam, officially the Socialist Republic of Vietnam (SRV), is a country at the eastern edge of mainland Southeast Asia, with an area of about and a population of over 100 million, making it the world's List of countries and depende ...
(see Domino Theory). The Korean War began in 1950, when the Soviets walked out of a U.N. Security Council meeting, removing their possible veto. Under a
United Nations The United Nations (UN) is the Earth, global intergovernmental organization established by the signing of the Charter of the United Nations, UN Charter on 26 June 1945 with the stated purpose of maintaining international peace and internationa ...
umbrella, hundreds of thousands of U.S. troops fought to prevent the takeover of
South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia. It constitutes the southern half of the Korea, Korean Peninsula and borders North Korea along the Korean Demilitarized Zone, with the Yellow Sea to the west and t ...
by
North Korea North Korea, officially the Democratic People's Republic of Korea (DPRK), is a country in East Asia. It constitutes the northern half of the Korea, Korean Peninsula and borders China and Russia to the north at the Yalu River, Yalu (Amnok) an ...
, and later, to invade the northern nation. After repeated advances and retreats by both sides, and the PRC People's Volunteer Army entry into the war, the Korean Armistice Agreement ended the war and returned the peninsula to the status quo in 1953. During the 1950s, the Pentomic reorganization shifted the basic tactical unit from the regiment to the five-company battle group. Armored divisions did not change during the Pentomic era. Instead of brigades, an armored division had three Combat Commands designated: CCA, CCB, and CCC. On 16 December 1960, the Army Chief of Staff directed a reappraisal of division organization. Resulting studies were carried out between January and April 1961, and fully implemented by 1965. The resulting Reorganization of Army Divisions (ROAD) program shifted all types of divisions (Mechanized, Airborne, Armor, Infantry and Cavalry) to an identical structure of three brigades of three (sometimes four) battalions. The ROAD division consisted of a mix of nine to twelve armor and infantry battalions assigned to the division to meet the expected needs of the division based on its Mission, the likely Enemy, the Terrain/weather, and other forces available or Troops (METT). Each brigade would be assigned or attached the mix of battalions and companies based on the division commanders estimate based on METT. As operations continued, the division commander could task organize subordinate units as needed by the flow of the battle. The 1st Air Cavalry in Vietnam had nine battalions spread as needed between the three brigade headquarters, but often moved the equivalent of one battalion each day by airlift from one side of the battlefield to the other. An infantry battalion commander in 1st Infantry Division in Vietnam could expect having the number of companies under his command change at least once a day, with companies from different divisions not uncommon. In the "Heavy" divisions in Europe, a tank or infantry company could find itself moved to other battalions more than once a week, and to another brigade as needed.


Vietnam

The
Vietnam War The Vietnam War (1 November 1955 – 30 April 1975) was an armed conflict in Vietnam, Laos, and Cambodia fought between North Vietnam (Democratic Republic of Vietnam) and South Vietnam (Republic of Vietnam) and their allies. North Vietnam w ...
is often regarded as a low point in the Army's record due to the extensive use of drafted enlisted personnel versus mobilization of Army Reserve and
Army National Guard The Army National Guard (ARNG) is an organized Militia (United States), militia force and a Reserve components of the United States Armed Forces, federal military reserve force of the United States Army. It is simultaneously part of two differen ...
personnel, the unpopularity of the war with the American public, and frustrating restrictions placed on the Army by U.S. political leaders (i.e., no invasion of communist-held
North Vietnam North Vietnam, officially the Democratic Republic of Vietnam (DRV; ; VNDCCH), was a country in Southeast Asia from 1945 to 1976, with sovereignty fully recognized in 1954 Geneva Conference, 1954. A member of the communist Eastern Bloc, it o ...
). While American forces had been stationed in the Republic of Vietnam since 1959, in intelligence and advisory/training roles, they did not deploy in large numbers until 1965, after the Gulf of Tonkin Incident. American forces effectively established and maintained control of the "traditional" battlefield, however they struggled to counter the
guerrilla Guerrilla warfare is a form of unconventional warfare in which small groups of irregular military, such as rebels, Partisan (military), partisans, paramilitary personnel or armed civilians, which may include Children in the military, recruite ...
hit and run tactics of the communist Viet Cong and the North Vietnamese Army. For instance in the Tet Offensive in 1968, the U.S. Army turned a large scale attack by communist forces into a massive defeat of the Viet Cong on the battlefield (though at the time the offensive sapped the political will of the American public) which permanently weakened the guerrilla force. Thereafter, most large scale engagements were fought with the regular North Vietnamese Army. In 1973 domestic political opposition to the war finally forced a U.S. withdrawal. In 1975, Vietnam was unified under a communist government. During the 1960s the Department of Defense continued to scrutinize the reserve forces and to question the number of divisions and brigades as well as the redundancy of maintaining two reserve components, the
Army National Guard The Army National Guard (ARNG) is an organized Militia (United States), militia force and a Reserve components of the United States Armed Forces, federal military reserve force of the United States Army. It is simultaneously part of two differen ...
and the Army Reserve. In 1967 Secretary of Defense
Robert McNamara Robert Strange McNamara (; June 9, 1916 – July 6, 2009) was an American businessman and government official who served as the eighth United States secretary of defense from 1961 to 1968 under presidents John F. Kennedy and Lyndon B. Johnson ...
decided that 15 combat divisions in the Army National Guard were unnecessary and cut the number to 8 divisions (1 mechanized infantry, 2 armored, and 5 infantry), but increased the number of brigades from 7 to 18 (1 airborne, 1 armored, 2 mechanized infantry, and 14 infantry). The loss of the divisions did not set well with the states. Their objections included the inadequate maneuver element mix for those that remained and the end to the practice of rotating divisional commands among the states that supported them. Under the proposal, the remaining division commanders were to reside in the state of the division base. No reduction, however, in total Army National Guard strength was to take place, which convinced the governors to accept the plan. The states reorganized their forces accordingly between 1 December 1967 and 1 May 1968.


Post Vietnam War

A "Total Force Policy" was adopted by Chief of Staff of the Army General
Creighton Abrams Creighton Williams Abrams Jr. (15 September 1914 – 4 September 1974) was a United States Army General (United States), general who commanded military operations in the Vietnam War from 1968 to 1972. He was then Chief of Staff of the United Sta ...
in the aftermath of the Vietnam War and involved treating the three components of the Army – the
Regular Army A regular army is the official army of a state or country (the official armed forces), contrasting with irregular forces, such as volunteer irregular militias, private armies, mercenaries, etc. A regular army usually has the following: * a ...
, the
Army National Guard The Army National Guard (ARNG) is an organized Militia (United States), militia force and a Reserve components of the United States Armed Forces, federal military reserve force of the United States Army. It is simultaneously part of two differen ...
and the Army Reserve as a single force. Training and Doctrine Command was established as a major U.S. Army command on 1 July 1973. The new command, along with the U.S. Army Forces Command (FORSCOM), was created from the Continental Army Command (CONARC) located at Fort Monroe, Virginia. That action was the major innovation in the Army's post-Vietnam reorganization, born of the realization that CONARC's obligations and span of control were too broad for efficient focus. The new organization functionally realigned the major Army commands in the continental United States. CONARC, and Headquarters, as well as U.S. Army Combat Developments Command (CDC), situated at Fort Belvoir, Virginia, were discontinued, with TRADOC and FORSCOM at Fort Belvoir assuming the realigned missions. TRADOC assumed the doctrine development mission from CDC and took over the individual training mission formerly the responsibility of CONARC. The new command also assumed control from CONARC of the major Army installations in the United States housing Army training centers and branch schools. FORSCOM assumed CONARC's operational responsibility for the command and readiness of all divisions and corps in the continental U.S. and for the installations where they were based. The 1980s was mostly a decade of reorganization. The Army converted to an all-volunteer force with greater emphasis on training and technology. The Goldwater–Nichols Act of 1986 created Unified Combatant Commands, bringing the Army together with the other three military branches under unified, geographically-organized command structures. The Army also played a role in the invasions of
Grenada Grenada is an island country of the West Indies in the eastern Caribbean Sea. The southernmost of the Windward Islands, Grenada is directly south of Saint Vincent and the Grenadines and about north of Trinidad and Tobago, Trinidad and the So ...
in 1983 ( Operation Urgent Fury) and
Panama Panama, officially the Republic of Panama, is a country in Latin America at the southern end of Central America, bordering South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and ...
in 1989 ( Operation Just Cause). By 1989, Germany was nearing reunification and the Cold War was coming to a close. Army leadership reacted by starting to plan for a reduction in strength. By November 1989, Pentagon briefers were laying out plans for Operation Quicksilver, a plan to reduce Army endstrength by 23%, from 750,000 to 580,000. A number of incentives were used to accomplish this reduction, including early retirement.


Force Structure 1989

The Active Army Force Structure in 1989 at the end of the
Cold War The Cold War was a period of global Geopolitics, geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which lasted from 1947 unt ...
was: * United States Army Forces Command (FORSCOM), at
Fort Bragg Fort Bragg (formerly Fort Liberty from 2023–2025) is a United States Army, U.S. Army Military base, military installation located in North Carolina. It ranks among the largest military bases in the world by population, with more than 52,000 m ...
( NC) ** I Corps, at Fort Lewis (
Washington (state) Washington, officially the State of Washington, is a U.S. state, state in the Pacific Northwest region of the United States. It is often referred to as Washington State to distinguish it from Washington, D.C., the national capital, both n ...
) *** 7th Infantry Division (Light), at Fort Ord ( CA) *** 9th Infantry Division (Motorized)Note 1, at Fort Lewis (WA) ** III Corps, at Fort Hood ( TX);
NATO The North Atlantic Treaty Organization (NATO ; , OTAN), also called the North Atlantic Alliance, is an intergovernmental organization, intergovernmental Transnationalism, transnational military alliance of 32 Member states of NATO, member s ...
Northern Army Group (NORTHAG) REFORGER corps *** 1st Cavalry Division, organized as an armored division;Note 1, at Fort Hood (TX); REFORGER unit with POMCUS depots at Grobbendonk and Zutendaal (
Belgium Belgium, officially the Kingdom of Belgium, is a country in Northwestern Europe. Situated in a coastal lowland region known as the Low Countries, it is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeas ...
), and Brunssum and Eygelshoven (
Netherlands , Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...
) *** 2nd Armored Division (-), at Fort Hood (TX); REFORGER unit with POMCUS depots in
Mönchengladbach Mönchengladbach (, ) is a List of cities and towns in Germany, city in North Rhine-Westphalia, western Germany, west of the Rhine, halfway between Düsseldorf and the Netherlands, Dutch border. Geography Municipal subdivisions Since 2009, th ...
and Straelen (GER) *** 5th Infantry Division (Mechanized)Note 1, at Fort Polk ( LA); REFORGER unit with POMCUS depots in Ter Apel, Coevorden and Vriezenveen (Netherlands) *** 3rd Armored Cavalry Regiment, at
Fort Bliss Fort Bliss is a United States Army post in New Mexico and Texas, with its headquarters in El Paso, Texas. Established in 1848, the fort was renamed in 1854 to honor William Wallace Smith Bliss, Bvt.Lieut.Colonel William W.S. Bliss (1815–1853 ...
(TX); REFORGER unit with POMCUS depots in
Mönchengladbach Mönchengladbach (, ) is a List of cities and towns in Germany, city in North Rhine-Westphalia, western Germany, west of the Rhine, halfway between Düsseldorf and the Netherlands, Dutch border. Geography Municipal subdivisions Since 2009, th ...
(GER) ** XVIII Airborne Corps, at Fort Bragg (NC) ***
82nd Airborne Division The 82nd Airborne Division is an Airborne forces, airborne infantry division (military), division of the United States Army specializing in Paratrooper, parachute assault operations into hostile areasSof, Eric"82nd Airborne Division" ''Spec Ops ...
, at Fort Bragg (NC) *** 101st Airborne Division (Air Assault), at Fort Campbell ( KY) *** 10th Mountain Division (Light)Note 1, at Fort Drum ( NY) *** 24th Infantry Division (Mechanized)Note 1, at Fort Stewart ( GA) ** 1st Infantry Division (Mechanized) (-), at Fort Riley ( KS); VII Corps REFORGER unit with POMCUS depots in
Mannheim Mannheim (; Palatine German language, Palatine German: or ), officially the University City of Mannheim (), is the List of cities in Baden-Württemberg by population, second-largest city in Baden-Württemberg after Stuttgart, the States of Ger ...
(GER) ** 4th Infantry Division (Mechanized), at Fort Carson ( CO); V Corps REFORGER unit with POMCUS depots in Kaiserslautern (GER) ** 6th Infantry Division (Light)Note 2, at Fort Richardson ( AK); part of United States Army Alaska, which was assigned to WESTCOM in 1989 ** 194th Armored Brigade, at Fort Knox (KY); V Corps REFORGER unit with POMCUS depots in Pirmasens (GER) ** 193rd Infantry Brigade, at Fort Clayton (
Panama Canal Zone The Panama Canal Zone (), also known as just the Canal Zone, was a International zone#Concessions, concession of the United States located in the Isthmus of Panama that existed from 1903 to 1979. It consisted of the Panama Canal and an area gene ...
) ** 197th Infantry Brigade, at
Fort Benning Fort Benning (named Fort Moore from 2023–2025) is a United States Army post in the Columbus, Georgia area. Located on Georgia's border with Alabama, Fort Benning supports more than 120,000 active-duty military, family members, reserve compone ...
(GA); V Corps REFORGER unit with POMCUS depots in Pirmasens (GER) * United States Army Europe (USAREUR), in
Stuttgart Stuttgart (; ; Swabian German, Swabian: ; Alemannic German, Alemannic: ; Italian language, Italian: ; ) is the capital city, capital and List of cities in Baden-Württemberg by population, largest city of the States of Germany, German state of ...
(
Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...
(GER)) ** V Corps, in
Frankfurt Frankfurt am Main () is the most populous city in the States of Germany, German state of Hesse. Its 773,068 inhabitants as of 2022 make it the List of cities in Germany by population, fifth-most populous city in Germany. Located in the forela ...
(GER) *** 3rd Armored Division, in Frankfurt *** 8th Infantry Division (Mechanized), in Bad Kreuznach *** 11th Armored Cavalry Regiment, in Fulda ** VII Corps, in Stuttgart (GER) *** 1st Armored Division, in
Ansbach Ansbach ( , ; ) is a city in the Germany, German state of Bavaria. It is the capital of the Regierungsbezirk, administrative region of Mittelfranken, Middle Franconia. Ansbach is southwest of Nuremberg and north of Munich, on the river Fränk ...
*** 1st Infantry Division (Forward) (3rd Brigade, 1st Infantry Division), in Göppingen *** 3rd Infantry Division (Mechanized), in
Würzburg Würzburg (; Main-Franconian: ) is, after Nuremberg and Fürth, the Franconia#Towns and cities, third-largest city in Franconia located in the north of Bavaria. Würzburg is the administrative seat of the Regierungsbezirk Lower Franconia. It sp ...
*** 2nd Armored Cavalry Regiment, in
Nuremberg Nuremberg (, ; ; in the local East Franconian dialect: ''Nämberch'' ) is the Franconia#Towns and cities, largest city in Franconia, the List of cities in Bavaria by population, second-largest city in the States of Germany, German state of Bav ...
** 2nd Armored Division (Forward) (3rd Brigade, 2nd Armored Division), in Garlstedt ** Berlin Brigade, in
West Berlin West Berlin ( or , ) was a political enclave which comprised the western part of Berlin from 1948 until 1990, during the Cold War. Although West Berlin lacked any sovereignty and was under military occupation until German reunification in 1 ...
* United States Army Western Command (WESTCOM), at Fort Shafter ( HI); part of US Pacific Command, added US Army Alaska in 1989 and US Army, Japan in 1990 ** 25th Infantry Division (Light), at Schofield Barracks (HI) *
Eighth United States Army The Eighth Army is a U.S. field army which commands all United States Army forces in South Korea. It is headquartered at the Camp Humphreys in the Anjeong-ri of Pyeongtaek, Pyeongtaek, South Korea.Yongsan Garrison (
South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia. It constitutes the southern half of the Korea, Korean Peninsula and borders North Korea along the Korean Demilitarized Zone, with the Yellow Sea to the west and t ...
) ** 2nd Infantry Division, at Camp Casey (South Korea) * United States Army Japan/ IX Corps, at Camp Zama (
Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...
) Note 1: division fielded two active Army and one
Army National Guard The Army National Guard (ARNG) is an organized Militia (United States), militia force and a Reserve components of the United States Armed Forces, federal military reserve force of the United States Army. It is simultaneously part of two differen ...
roundout brigade.

Note 2: division fielded two active Army and one Army Reserve roundout brigade. Additionally the 177th Armored Brigade acted as Opposing Force ( OPFOR) at the National Training Center (NTC) at Fort Irwin in California. The
Army National Guard The Army National Guard (ARNG) is an organized Militia (United States), militia force and a Reserve components of the United States Armed Forces, federal military reserve force of the United States Army. It is simultaneously part of two differen ...
fielded six infantry, two mechanized, and two armored divisions for a total of ten National Guard divisions, as well as 18 separate combat brigades (11x infantry, 3x armored, 4x mechanized) and three armored cavalry regiments. The Army Reserve fielded one mechanized and two infantry brigades.


1990s

In 1990,
Iraq Iraq, officially the Republic of Iraq, is a country in West Asia. It is bordered by Saudi Arabia to Iraq–Saudi Arabia border, the south, Turkey to Iraq–Turkey border, the north, Iran to Iran–Iraq border, the east, the Persian Gulf and ...
invaded its smaller neighbor,
Kuwait Kuwait, officially the State of Kuwait, is a country in West Asia and the geopolitical region known as the Middle East. It is situated in the northern edge of the Arabian Peninsula at the head of the Persian Gulf, bordering Iraq to Iraq–Kuwait ...
, and U.S. land forces, led by the
82nd Airborne Division The 82nd Airborne Division is an Airborne forces, airborne infantry division (military), division of the United States Army specializing in Paratrooper, parachute assault operations into hostile areasSof, Eric"82nd Airborne Division" ''Spec Ops ...
, quickly deployed to assure the protection of
Saudi Arabia Saudi Arabia, officially the Kingdom of Saudi Arabia (KSA), is a country in West Asia. Located in the centre of the Middle East, it covers the bulk of the Arabian Peninsula and has a land area of about , making it the List of Asian countries ...
. In January 1991, Operation Desert Storm commenced, and a U.S.-led coalition deployed over 500,000 troops, the bulk of them from U.S. Army formations, to drive out Iraqi forces. The campaign ended in a victory for coalition forces, swiftly routing an
Iraqi Army The Iraqi Ground Forces (Arabic: القوات البرية العراقية), also referred to as the Iraqi Army (Arabic: الجيش العراقي), is the ground force component of the Iraqi Armed Forces. It was formerly known as the Royal Iraq ...
organized along Soviet lines in just one hundred hours. Later in 1991 the Soviet Union was dissolved, effectively ending the Cold War. After Desert Storm the Army did not see major combat operations for the remainder of the 1990s. Army units did participate in a number of peacekeeping activities, such as the UN peacekeeping mission in
Somalia Somalia, officially the Federal Republic of Somalia, is the easternmost country in continental Africa. The country is located in the Horn of Africa and is bordered by Ethiopia to the west, Djibouti to the northwest, Kenya to the southwest, th ...
in 1993, where the abortive Operation Gothic Serpent led to the deaths of eighteen American soldiers and the withdrawal of international forces. The Army also contributed troops to NATO peacekeeping forces in the
Yugoslav Wars The Yugoslav Wars were a series of separate but related#Naimark, Naimark (2003), p. xvii. ethnic conflicts, wars of independence, and Insurgency, insurgencies that took place from 1991 to 2001 in what had been the Socialist Federal Republic of ...
from December 1995, initially with the Implementation Force during the
Bosnian War The Bosnian War ( / Рат у Босни и Херцеговини) was an international armed conflict that took place in Republic of Bosnia and Herzegovina, Bosnia and Herzegovina between 1992 and 1995. Following several earlier violent incid ...
. U.S. Army forces only left Bosnia and Herzegovina in 2004 with the disestablishment of Task Force Eagle on November 24, 2004. U.S. Army troops remain in Kosovo with the
Kosovo Force The Kosovo Force (KFOR) is a North Atlantic Treaty Organization, NATO-led international NATO peacekeeping, peacekeeping force and military of Kosovo. KFOR is the third security responder, after the Kosovo Police and the EU Rule of Law (European ...
. During the first half of the decade the Army deactivated 8 of its 18 active divisions: * 9th Infantry Division (Motorized) in 1991 * 3d Armored Division in 1992 * 5th Infantry Division (Mechanized) in 1992 * 8th Infantry Division (Mechanized) in 1992 * 6th Infantry Division (Light) in 1994 * 7th Infantry Division (Light) in 1994 * 2d Armored Division in 1995 * 24th Infantry Division (Mechanized) in 1996 as well as two of its ten National Guard divisions: * 50th Armored Division in 1993 * 26th Infantry Division (Light) in 1993 Plans to convert two Army National Guard divisions to cadre formations were rejected by Congress in 1992. During the mid-late 1990s, the Army trialled Force XXI. One of its initiatives was Task Force 21 (also called Task Force XXI), a battlefield digitized
brigade A brigade is a major tactical military unit, military formation that typically comprises three to six battalions plus supporting elements. It is roughly equivalent to an enlarged or reinforced regiment. Two or more brigades may constitute ...
formed for the Advanced Warfighting Exercises in 1997 to test Force XXI concepts, technology, and tactics. The brigade was formed from the 4th Infantry Division (which replaced the deactivated 2d Armored Division in 1992) and the 1st Cavalry Division as early as 1992, with some field testing beginning at Fort Hood in late 1992, early 1993. The 4th Infantry Division units assigned were 3–66 Armor and 1–22 Infantry, both of the 3d Brigade, while 1st Cavalry Division drew soldiers across a variety of support and combat fields. Technologies tested included Software-defined radios, Applique computers, Ground Surveillance Radar, Satellite radio email systems, and Advanced UAV technology. TF-XXI participated in various Advanced Warfighting Exercises, including WARRIOR FOCUS (1995 #4).


Twenty-first century

On 11 September 2001, 53 Army civilians (47 employees and six contractors) and 22 soldiers were among the 125 victims killed in
the Pentagon The Pentagon is the headquarters building of the United States Department of Defense, in Arlington County, Virginia, across the Potomac River from Washington, D.C. The building was constructed on an accelerated schedule during World War II. As ...
in a
terrorist attack Terrorism, in its broadest sense, is the use of violence against non-combatants to achieve political or ideological aims. The term is used in this regard primarily to refer to intentional violence during peacetime or in the context of war a ...
when American Airlines Flight 77 commandeered by five
Al-Qaeda , image = Flag of Jihad.svg , caption = Jihadist flag, Flag used by various al-Qaeda factions , founder = Osama bin Laden{{Assassinated, Killing of Osama bin Laden , leaders = {{Plainlist, * Osama bin Lad ...
hijackers slammed into the western side of the building as part of the September 11 attacks.
Lieutenant General Lieutenant general (Lt Gen, LTG and similar) is a military rank used in many countries. The rank traces its origins to the Middle Ages, where the title of lieutenant general was held by the second-in-command on the battlefield, who was norma ...
Timothy Maude was the highest-ranking military official killed at the Pentagon, and the most senior U.S. Army officer killed by foreign action since the death of Lieutenant General Simon Bolivar Buckner Jr. on June 18, 1945, in the
Battle of Okinawa The , codenamed Operation Iceberg, was a major battle of the Pacific War fought on the island of Okinawa Island, Okinawa by United States Army and United States Marine Corps forces against the Imperial Japanese Army during the Pacific War, Impe ...
during
World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
. In response to the September 11 attacks, U.S. and NATO forces invaded Afghanistan in October 2001, replacing the Taliban government. This began the " war on terror." The Army took part in the U.S. 2003 invasion of Iraq, supported by the United Kingdom, Poland, and Australia. Within months, the mission changed from conflict between regular forces to counterinsurgency, with large numbers of suicide attacks resulting in the deaths of more than 4,000 U.S. service members (as of March 2008) and injuries to thousands more. Most of the units that carried out the ground campaign phase of the invasion of Iraq, and who bore the larger part of the conflict with the Iraqi Armed Forces in 2003, were those of the Army. Since then, they have performed numerous operations against insurgents. The Army has had to make several adjustments to address demands on its personnel and equipment. The US Army has utilized its stop-loss policy and has required more of its combat personnel to serve more tours of duty than before due to the need for experienced personnel. Unlike during the war in Vietnam, there was no involuntary draft of Americans into the Army. Instead, the service employed its Total Force model and mobilized/recalled to active duty numerous
Army National Guard The Army National Guard (ARNG) is an organized Militia (United States), militia force and a Reserve components of the United States Armed Forces, federal military reserve force of the United States Army. It is simultaneously part of two differen ...
and Army Reserve combat arms, combat support, and combat service support units and personnel, often deploying them repeatedly to the Southwest Asia combat zone in a manner similar to their Regular Army counterparts. As a result of this intense operational tempo, deep concerns arose in the U.S. about the effects of frequent combat deployment on the psychological health of US soldiers in Iraq and Afghanistan. Suicides among US soldiers have been rising, and have reached their highest rate in 26 years. This increase has coincided with US deployments in Afghanistan and Iraq. During the insurgency, it was found that most Army and Marine Corps vehicles such as HMMWVs were insufficiently armored, leading to efforts to add greater armor to protect against improvised explosive devices. Some soldiers added armor by using modifications known as hillbilly armor. In the short term, HMMWVs in service in Iraq are being replaced by Category 1
MRAP Mine-Resistant Ambush Protected Vehicle (MRAPV), also known as MRAP vehicle, is a type of armoured personnel carrier that is designed specifically to withstand land mines, improvised explosive device (IED) attacks, and ambushes to save troops' li ...
vehicles, primarily the
Force Protection Force protection (FP) is the concept of protecting military personnel, family members, civilians, facilities, equipment and operations from threats or hazards in order to preserve operational effectiveness and contribute to mission success. It ...
Cougar H and the
International MaxxPro The International M1224 MaxxPro Mine-Resistant Ambush Protected Vehicle, MRAP (Mine-Resistant Ambush Protected) is an armored fighting vehicle designed by American company Navistar International's subsidiary Navistar Defense along with the Israe ...
. The US Marine Corps plans to replace all HMMWVs patrolling "outside the wire" with MRAP vehicles. The lack of stability in Iraq has led to longer deployments for Regular Army as well as Army Reserve and Army National Guard troops. U.S. troops withdrew in December 2011, but fighting continues. 3,293 US Army personnel were killed in the conflict.Hampson, Rick, "West Point's Quiet Place Of Honor, Lost Dreams", ''
USA Today ''USA Today'' (often stylized in all caps) is an American daily middle-market newspaper and news broadcasting company. Founded by Al Neuharth in 1980 and launched on September 14, 1982, the newspaper operates from Gannett's corporate headq ...
'', 28 December 2011, p. 1.
The Army's chief modernization plan was the Future Combat Systems program. Many systems were canceled and the remaining were swept into the BCT modernization program.


Personnel strength

* 1775–1783: 17,000 (
Continental Army The Continental Army was the army of the United Colonies representing the Thirteen Colonies and later the United States during the American Revolutionary War. It was formed on June 14, 1775, by a resolution passed by the Second Continental Co ...
without militias) * 1784: 700 ( First American Regiment) * 1793: 5,100 ( Legion of the United States) * 1812: 7,000 * 1815: 35,800 * 1846: 8,600 * 1848: 32,000 * 1861: 16,400 (
Regular Army A regular army is the official army of a state or country (the official armed forces), contrasting with irregular forces, such as volunteer irregular militias, private armies, mercenaries, etc. A regular army usually has the following: * a ...
, before the
American Civil War The American Civil War (April 12, 1861May 26, 1865; also known by Names of the American Civil War, other names) was a civil war in the United States between the Union (American Civil War), Union ("the North") and the Confederate States of A ...
) * 1865: 1,000,500 ( Union Army including volunteer units) * 1869: 39,000 * 1870: 30,000 * 1874: 25,000 * 1898: 25,000 * 1917: 286,000 * 1939: 189,800 * 1945: 8,268,000 * 2017: 460,000 * 2020: 480,900 * 2023: 453,551 Numbers rounded up or down to full thousands or to full hundreds, if more precisely known.


See also

* Military history of the United States * Social history of soldiers and veterans in the United States * List of military weapons of the United States ** History of the United States Navy ** History of the United States Marine Corps ** History of the United States Air Force ** History of the United States Coast Guard * Organizations which deal with US Army History **
United States Army Center of Military History The United States Army Center of Military History (CMH) is a directorate within the United States Army Training and Doctrine Command. The Institute of Heraldry remains within the Office of the Administrative Assistant to the Secretary of the Arm ...
*** Military history detachments ** Army Historical Foundation ** U.S. Army Heritage and Education Center * Other topics ** U.S. Army Birthdays


Notes


References

* "Case Reference Guide for Review of Military Records", Military Personnel Records Center, published 2001 * "Army Force Components Training Guide", Military Personnel Records Center, published 2003 * Wilson, John B. (1997). Maneuver and Firepower: The Evolution of Divisions and Separate Brigades. Washington, DC: Center of Military History. * United States Army Service Records (1910–2005), National Personnel Records Center, Overland, Missouri


Further reading

* Abrahamson, James L. ''America Arms for a New Century: The Making of a Great Military Power'' (1981), examines reformers and modernizers * Anderson, Fred, ed. ''The Oxford Companion to American Military History'' (2000) * Bailey, Beth. ''America's Army: Making the All-Volunteer Force Hardcover'' (2009
excerpt
* Black, Jeremy. ''America as a Military Power: From the American Revolution to the Civil War'' (2002) * * Bontrager, Shannon. ''Death at the Edges of Empire: Fallen Soldiers, Cultural Memory, and the Making of an American Nation, 1863-1921'' (University of Nebraska Press, 2020); memories of American war dead
online summary by author
* Carp, E. Wayne. ''To Starve the Army at Pleasure: Continental Army Administration and American Political Culture, 1775–1783.'' ( U of North Carolina Press, 1984). * Carter, Donald A. ''Forging the Shield: The U.S. Army in Europe, 1951-1962'' (Washington: Center of Military History, 2015). xxiv, 513 pp. * Center for Military History. U.S. Army Campaigns of the War of 1812

** Barbuto, Richard V. ''The Canadian Theater 1813''. (2013) ** Barbuto, Richard V. ''The Canadian Theater 1814''. (2014) ** Blackmon, Richard D. ''The Creek War 1813–1814''; 43pp ** Neimeyer, Charles P. ''The Chesapeake Campaign, 1813–1814'' (2014) ** Rauch, Steven J. ''The Campaign of 1812'' (2013); 58pp ** Stoltz III, Joseph F. ''The Gulf Theater, 1813–1815'' * Chambers, ed. John Whiteclay. ''The Oxford Guide to American Military History'' (1999) online at many libraries * Clark, J. P. ''Preparing for War: The Emergence of the Modern U.S. Army, 1815–1917'' (Harvard UP, 2017) 336 pp. * Coffman, Edward M. ''The Regulars: The American Army, 1898–1941'' (2007
excerpt and text search
* Coffman, Edward M. ''The War to End All Wars: The American Military Experience in World War I'' (1998), a standard history * Coumbe, Arthur T
''A History of the U.S. Army Officer Corps, 1900–1990''
(2014). Carlisle, PA : Strategic Studies Institute,
U.S. Army War College The United States Army War College (USAWC) is a United States Army, U.S. Army staff college in Carlisle Barracks, Pennsylvania, with a Carlisle, Pennsylvania, Carlisle postal address, on the 500-acre (2 km2) campus of the historic Carlisle B ...
Press. * Doughty, Robert. ''American Military History and the Evolution of Western Warfare'', (1996), stress on combat operations * Faulkner, Richard S. ''Pershing's Crusaders: The American Soldier in World War I'' (U Press of Kansas, 2017). xiv, 758 pp * Herrera, Ricardo A. ''For Liberty and the Republic: The American Citizen as Soldier, 1775–1861'' (New York University Press, 2015
online review
* Higginbotham, Don. ''The War of American Independence: Military Attitudes, Policies, and Practice, 1763–1789'' (1971, 1983). an analytical history of the wa
online via ACLS Humanities E-Book.
* Hope, Ian C. ''A Scientific Way of War: Antebellum Military Science, West Point, and the Origins of American Military Thought'' (U of Nebraska Press, 2015). xii, 334 pp. * Huston, James A. ''The Sinews of War: Army Logistics, 1775–1953'' (1966), U.S. Army; pp. 755
online
* Krebs, Daniel, and Lorien Foote, eds. ''Useful Captives: The Role of POWs in American Military Conflicts'' ( University Press of Kansas, 2021). covers American POWs and POWs held by U.S. * Kretchik, Walter E. ''U.S. Army Doctrine: From the American Revolution to the War on Terror'' (University Press of Kansas; 2011) 392 pages; studies military doctrine in four distinct eras: 1779–1904, 1905–1944, 1944–1962, and 1962 to the present. * Gillett, Mary C. ''The Army Medical Department, 1775–1818.'' Washington: Center of Military History, U.S. Army, 1981. * Kimball, Jeffrey. "The Influence of Ideology on Interpretive Disagreement: A Report on a Survey of Diplomatic, Military and Peace Historians on the Causes of 20th Century U. S. Wars," ''History Teacher'' 17#3 (1984) pp. 355–384 DOI: 10.2307/493146
online
* Maass, John R. ''Defending A New Nation 1783–1811'' (Center for Military History, 2013) 59p
online
* Matloff, Maurice, ed. ''American Military History'' (1996

; standard textbook used in ROTC * * Millett, Allan R., and Peter Maslowski. ''For the common defense: a military history of the United States of America'' (1984) * Neimeyer, Charles Patrick. ''America Goes to War: A Social History of the Continental Army'' (1995
complete text online
* Newell, Clayton R
The Regular Army before the Civil War, 1845–1860.
Washington, DC: Center of Military History, United States Army, 2014. * Olinger, Mark A., "Organizing for War in Canada, 1812–1814: The U.S. Army Experience," ''Ontario History'' 104 (Spring 2012), 21–44. * Oyos, Matthew. "Courage, Careers, and Comrades: Theodore Roosevelt and the United States Army Officer Corps," ''Journal of the Gilded Age & Progressive Era'' (2011) 10#1 pp. 23–58. On TR's controversial reforms that included physical testing and rapid promotion of younger talent. * * Royster, Charles. ''A Revolutionary People at War: The Continental Army and American Character, 1775–1783.'' Chapel Hill: University of North Carolina Press, 1979. . * Schifferle, Peter J. ''America's School for War: Fort Leavenworth, Officer Educations, and Victory in World War II''. Lawrence: University Press of Kansas, 2010. * Shannon, Fred. ''The Organization and Administration of the Union Army 1861–1865'' (2 vol 1928
vol 1 excerpt and text searchvol 2 excerpt and text search
* Sweeney, Jerry K., and Kevin B. Byrne, eds. ''A Handbook of American Military History: From the Revolutionary War to the Present'', (1997) * Weigley, Russell Frank. ''The American Way of War: A History of United States Military Strategy and Policy'', (1977) * Utley, Robert M. ''Frontier Regulars; the United States Army and the Indian, 1866–1891'' (1973) * ; * Wintermute, Bobby A., "'The Negro Should Not Be Used as a Combat Soldier': Reconfiguring Racial Identity in the United States Army, 1890–1918," ''Patterns of Prejudice'', 46 (July 2012), 277–98. * Woodward, David R. ''The American Army and the First World War'' (Cambridge University Press, 2014). 484 pp
online review


External links


H-WAR is the free daily H-Net network on world military history; announcements, book reviews, discussions.

History and Heritage of the U.S. Army
– from the official U.S. Army website
Army Historical Foundation

United States Army Center of Military History


– A booklet published by the
United States Army Center of Military History The United States Army Center of Military History (CMH) is a directorate within the United States Army Training and Doctrine Command. The Institute of Heraldry remains within the Office of the Administrative Assistant to the Secretary of the Arm ...

Online Bookshelf of Books and Research Resources
at the
United States Army Center of Military History The United States Army Center of Military History (CMH) is a directorate within the United States Army Training and Doctrine Command. The Institute of Heraldry remains within the Office of the Administrative Assistant to the Secretary of the Arm ...
* {{DEFAULTSORT:History Of The United States Army Military units and formations established in 1775 History of the United States by topic
Army An army, ground force or land force is an armed force that fights primarily on land. In the broadest sense, it is the land-based military branch, service branch or armed service of a nation or country. It may also include aviation assets by ...