The United States Marine Corps (USMC), also referred to as the United States Marines, is the
maritime land force service branch of the
United States Armed Forces
The United States Armed Forces are the military forces of the United States. The armed forces consists of six service branches: the Army, Marine Corps, Navy, Air Force, Space Force, and Coast Guard. The president of the United States is ...
responsible for conducting
expeditionary and
amphibious operations through
combined arms, implementing its own
infantry
Infantry is a military specialization which engages in ground combat on foot. Infantry generally consists of light infantry, mountain infantry, motorized infantry & mechanized infantry, airborne infantry, air assault infantry, and m ...
,
artillery
Artillery is a class of heavy military ranged weapons that launch munitions far beyond the range and power of infantry firearms. Early artillery development focused on the ability to breach defensive walls and fortifications during sieg ...
,
aerial, and
special operations
Special operations (S.O.) are military activities conducted, according to NATO, by "specially designated, organized, selected, trained, and equipped forces using unconventional techniques and modes of employment". Special operations may include ...
forces. The U.S. Marine Corps is one of the eight
uniformed services of the United States
The United States has eight federal uniformed services that commission officers as defined by Title 10 and subsequently structured and organized by Titles 10, 14, 32, 33 and 42 of the U.S. Code.
Uniformed services
The uniformed services ...
.
The Marine Corps has been part of the
U.S. Department of the Navy
The United States Department of the Navy (DoN) is one of the three military departments within the Department of Defense of the United States of America. It was established by an Act of Congress on 30 April 1798, at the urging of Secretary o ...
since 30 June 1834 with its sister service, the
United States Navy
The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...
. The USMC operates
installations on land and aboard sea-going
amphibious warfare ships around the world. Additionally, several of the Marines' tactical
aviation
Aviation includes the activities surrounding mechanical flight and the aircraft industry. ''Aircraft'' includes fixed-wing and rotary-wing types, morphable wings, wing-less lifting bodies, as well as lighter-than-air craft such as hot ...
squadrons, primarily Marine Fighter Attack squadrons, are also embedded in Navy
carrier air wing
A carrier air wing (abbreviated CVW) is an operational naval aviation organization composed of several aircraft squadrons and detachments of various types of fixed-wing and rotary-wing aircraft. Organized, equipped and trained to conduct modern ...
s and operate from the
aircraft carriers.
The history of the Marine Corps began when two
battalion
A battalion is a military unit, typically consisting of 300 to 1,200 soldiers commanded by a lieutenant colonel, and subdivided into a number of companies (usually each commanded by a major or a captain). In some countries, battalions are ...
s of
Continental Marines were formed on 10 November 1775 in
Philadelphia
Philadelphia, often called Philly, is the largest city in the Commonwealth of Pennsylvania, the sixth-largest city in the U.S., the second-largest city in both the Northeast megalopolis and Mid-Atlantic regions after New York City. Sinc ...
as a service branch of infantry troops capable of fighting both at sea and on shore. In the
Pacific theater of
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...
the Corps took the lead in a massive campaign of amphibious warfare,
advancing from island to island.
As of 2022, the USMC has around 177,200 active duty members and some 32,400 personnel in
reserve.
Mission
As outlined in and as originally introduced under the
National Security Act of 1947
The National Security Act of 1947 ( Pub.L.br>80-253 61 Stat.br>495 enacted July 26, 1947) was a law enacting major restructuring of the United States government's military and intelligence agencies following World War II. The majority of the prov ...
, three primary areas of responsibility for the U.S. Marine Corps are:
* Seizure or defense of advanced naval bases and other land operations to support
naval campaigns;
* Development of tactics, technique, and equipment used by amphibious landing forces in coordination with the
Army
An army (from Old French ''armee'', itself derived from the Latin verb ''armāre'', meaning "to arm", and related to the Latin noun ''arma'', meaning "arms" or "weapons"), ground force or land force is a fighting force that fights primarily on ...
and
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 ar ...
; and
* Such other duties as the
President or
Department of Defense may direct.
This last clause derives from similar language in the
Congressional
A congress is a formal meeting of the representatives of different countries, constituent states, organizations, trade unions, political parties, or other groups. The term originated in Late Middle English to denote an encounter (meeting of ...
acts ''"For the Better Organization of the Marine Corps"'' of 1834, and ''"Establishing and Organizing a Marine Corps"'' of 1798. In 1951, the
House of Representatives' Armed Services Committee called the clause "one of the most important statutory – and traditional – functions of the Marine Corps". It noted that the Corps has more often than not performed actions of a non-naval nature, including its famous actions in
Tripoli
Tripoli or Tripolis may refer to:
Cities and other geographic units Greece
*Tripoli, Greece, the capital of Arcadia, Greece
*Tripolis (region of Arcadia), a district in ancient Arcadia, Greece
* Tripolis (Larisaia), an ancient Greek city in t ...
, the
War of 1812
The War of 1812 (18 June 1812 – 17 February 1815) was fought by the United States of America and its indigenous allies against the United Kingdom and its allies in British North America, with limited participation by Spain in Florida. It ...
,
Chapultepec, and numerous
counter-insurgency
Counterinsurgency (COIN) is "the totality of actions aimed at defeating irregular forces". The Oxford English Dictionary defines counterinsurgency as any "military or political action taken against the activities of guerrillas or revolutionar ...
and occupational duties (such as those in Central America,
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...
, and the
Korean War
{{Infobox military conflict
, conflict = Korean War
, partof = the Cold War and the Korean conflict
, image = Korean War Montage 2.png
, image_size = 300px
, caption = Clockwise from top: ...
). While these actions are not accurately described as support of naval campaigns nor as amphibious warfare, their common thread is that they are of an expeditionary nature, using the mobility of the Navy to provide timely intervention in foreign affairs on behalf of American interests.
The
Marine Band, dubbed the "President's Own" by
Thomas Jefferson
Thomas Jefferson (April 13, 1743 – July 4, 1826) was an American statesman, diplomat, lawyer, architect, philosopher, and Founding Father who served as the third president of the United States from 1801 to 1809. He was previously the nati ...
, provides music for state functions at the
White House
The White House is the official residence and workplace of the president of the United States. It is located at 1600 Pennsylvania Avenue Northwest, Washington, D.C., NW in Washington, D.C., and has been the residence of every U.S. preside ...
. Marines from Ceremonial Companies A & B, quartered in
Marine Barracks, Washington, D.C.
Marine Barracks, Washington, D.C. is located at the corner of 8th and I Streets, Southeast in Washington, D.C. Established in 1801, it is a National Historic Landmark, the oldest post in the United States Marine Corps, the official residence of t ...
, guard presidential retreats, including
Camp David
Camp David is the country retreat for the president of the United States of America. It is located in the wooded hills of Catoctin Mountain Park, in Frederick County, Maryland, near the towns of Thurmont and Emmitsburg, about north-northwes ...
, and the marines of the Executive Flight Detachment of
HMX-1 provide helicopter transport to the President and
Vice President
A vice president, also director in British English, is an officer in government or business who is below the president (chief executive officer) in rank. It can also refer to executive vice presidents, signifying that the vice president is o ...
, with the radio call signs "
Marine One" and "Marine Two", respectively. The Executive Flight Detachment also provides helicopter transport to
Cabinet members and other
VIPs
A very important person or personage (VIP or V.I.P.) is a person who is accorded special privileges due to their high social status, influence or importance. The term was not common until sometime after World War 2 by RAF pilots.
Examples in ...
. By authority of the 1946 Foreign Service Act, the
Marine Security Guard
A Marine Security Guard (MSG), also known as a Marine Embassy Guard, is a member of the Marine Corps Embassy Security Group (formerly Marine Security Guard Battalion), a brigade-sized organization of the United States Marine Corps (USMC) whose de ...
s of the Marine Embassy Security Command provide security for American
embassies
A diplomatic mission or foreign mission is a group of people from a state or organization present in another state to represent the sending state or organization officially in the receiving or host state. In practice, the phrase usually deno ...
,
legations, and
consulates at more than 140 posts worldwide.
The relationship between the
Department of State and the U.S. Marine Corps is nearly as old as the Corps itself. For over 200 years, marines have served at the request of various
Secretaries of State. After
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...
, an alert, disciplined force was needed to protect American embassies, consulates, and legations throughout the world. In 1947, a proposal was made that the Department of Defense furnishes Marine Corps personnel for Foreign Service guard duty under the provisions of the Foreign Service Act of 1946. A formal Memorandum of Agreement was signed between the Department of State and the
Secretary of the Navy
The secretary of the Navy (or SECNAV) is a statutory officer () and the head (chief executive officer) of the Department of the Navy, a military department (component organization) within the United States Department of Defense.
By law, the se ...
on 15 December 1948, and 83 marines were deployed to overseas missions. During the first year of the program, 36 detachments were deployed worldwide.
Historical mission
The Marine Corps was founded to serve as an infantry unit aboard naval vessels and was responsible for the security of the ship and its crew by conducting offensive and defensive combat during
boarding actions and defending the ship's officers from
mutiny; to the latter end, their quarters on the ship were often strategically positioned between the officers' quarters and the rest of the vessel. Continental Marines manned raiding parties, both at sea and ashore. America's first amphibious assault landing occurred early in the
Revolutionary War on 3 March 1776 as the Marines gained control of
Fort Montagu and
Fort Nassau, a
British ammunition depot and naval port in
New Providence, the Bahamas. The role of the Marine Corps has expanded significantly since then; as the importance of its original naval mission declined with changing naval warfare doctrine and the professionalization of the naval service, the Corps adapted by focusing on formerly secondary missions ashore. The Advanced Base Doctrine of the early 20th century codified their combat duties ashore, outlining the use of marines in the seizure of bases and other duties on land to support naval campaigns.
Throughout the late 19th and 20th centuries, Marine detachments served aboard Navy cruisers, battleships and aircraft carriers. Marine detachments served in their traditional duties as a ship's landing force, manning the ship's weapons and providing shipboard security. Marine detachments were augmented by members of the ship's company for landing parties, such as in the
First Sumatran expedition of 1832, and continuing in the Caribbean and
Mexican campaigns of the early 20th centuries. Marines developed tactics and techniques of amphibious assault on defended coastlines in time for use in World War II.
During World War II, marines continued to serve on capital ships. They often were assigned to man anti-aircraft batteries.
In 1950, President
Harry Truman
Harry S. Truman (May 8, 1884December 26, 1972) was the 33rd president of the United States, serving from 1945 to 1953. A leader of the Democratic Party, he previously served as the 34th vice president from January to April 1945 under Frankli ...
responded to a message from U.S. Representative
Gordon L. McDonough. McDonough had urged President Truman to add Marine representation on the
Joint Chiefs of Staff
The Joint Chiefs of Staff (JCS) is the body of the most senior uniformed leaders within the United States Department of Defense, that advises the president of the United States, the secretary of defense, the Homeland Security Council and t ...
. President Truman, writing in a letter addressed to McDonough, stated that "The Marine Corps is the Navy's police force and as long as I am President that is what it will remain. They have a propaganda machine that is almost equal to
Stalin's." McDonough then inserte
President Truman's letter dated 29 August 1950, into the ''
Congressional Record
The ''Congressional Record'' is the official record of the proceedings and debates of the United States Congress, published by the United States Government Publishing Office and issued when Congress is in session. The Congressional Record In ...
''. Congressmen and Marine organizations reacted, calling President Truman's remarks an insult and demanded an apology. Truman apologized to the Marine commandant at the time, writing, "I sincerely regret the unfortunate choice of language which I used in my letter of August 29 to Congressman McDonough concerning the Marine Corps." While Truman had apologized for his metaphor, he did not alter his position that the Marine Corps should continue to report to the Navy secretary. He made amends only by making a surprise visit to the
Marine Corps League
The Marine Corps League is the only congressionally chartered United States Marine Corps-related veterans organization in the United States. Its congressional charter was approved by the 75th U.S. Congress and signed by President Franklin D. Roo ...
a few days later, when he reiterated, "When I make a mistake, I try to correct it. I try to make as few as possible." He received a standing ovation.
When gun cruisers were retired by the 1960s, the remaining Marine detachments were only seen on battleships and carriers. Its original mission of providing shipboard security ended in the 1990s.
Capabilities
The Marine Corps fulfills a critical military role as an amphibious warfare force. It is capable of
asymmetric warfare with
conventional,
irregular, and
hybrid forces. While the Marine Corps does not employ any unique capabilities, as a force it can rapidly deploy a combined-arms task force to almost anywhere in the world within days. The basic structure for all deployed units is a
Marine Air-Ground Task Force (MAGTF) that integrates a
ground combat element, an
aviation combat element and a
logistics combat element under a common
command element. While the creation of joint commands under the
Goldwater–Nichols Act has improved inter-service coordination between each branch, the Corps's ability to permanently maintain integrated multi-element task forces under a single command provides a smoother implementation of combined-arms warfare principles.

The close integration of disparate Marine units stems from an organizational culture centered on the infantry. Every other Marine capability exists to support the infantry. Unlike some Western militaries, the Corps remained conservative against theories proclaiming the ability of new weapons to win wars independently. For example,
Marine aviation has always been focused on
close air support
In military tactics, close air support (CAS) is defined as air action such as air strikes by fixed or rotary-winged aircraft against hostile targets near friendly forces and require detailed integration of each air mission with fire and movemen ...
and has remained largely uninfluenced by air power theories proclaiming that
strategic bombing
Strategic bombing is a military strategy used in total war with the goal of defeating the enemy by destroying its morale, its economic ability to produce and transport materiel to the theatres of military operations, or both. It is a systemati ...
can single-handedly win wars.
This focus on the infantry is matched with the doctrine of "Every marine
sa rifleman", a precept of Commandant
Alfred M. Gray, Jr., emphasizing the infantry combat abilities of every marine. All marines, regardless of
military specialization, receive training as a
rifleman
A rifleman is an infantry soldier armed with a rifled long gun. Although the rifleman role had its origin with 16th century hand cannoneers and 17th century musketeers, the term originated in the 18th century with the introduction of the rif ...
; and all officers receive additional training as infantry platoon commanders. During World War II at the
Battle of Wake Island, when all of the Marine aircraft were destroyed, pilots continued the fight as ground officers, leading supply clerks and cooks in a final defensive effort.
Flexibility of execution is implemented via an emphasis on "
commander's intent" as a guiding principle for carrying out orders, specifying the end state but leaving open the method of execution.
The amphibious assault techniques developed for World War II evolved, with the addition of
air assault
Air assault is the movement of ground-based military forces by vertical take-off and landing (VTOL) aircraft—such as the helicopter—to seize and hold key terrain which has not been fully secured, and to directly engage enemy forces behind ...
and
maneuver warfare doctrine, into the current "''Operational Maneuver from the Sea''" doctrine of
power projection
Power projection (or force projection or strength projection), in international relations, is the capacity of a state to deploy and sustain forces outside its territory. The ability of a state to project its power into an area may serve as an e ...
from the seas.
The Marines are credited with the development of helicopter insertion doctrine and were the earliest in the American military to widely adopt maneuver-warfare principles, which emphasize low-level initiative and flexible execution. In light of recent warfare that has strayed from the Corps's traditional missions,
the Marines have renewed an emphasis on amphibious capabilities.

The Marine Corps relies on the Navy for
sealift to provide its rapid deployment capabilities. In addition to basing a third of the
Fleet Marine Force in Japan,
Marine expeditionary units (MEU) are typically stationed at sea so they can function as first responders to international incidents.
To aid rapid deployment, the
Maritime Pre-Positioning System was developed: fleets of
container ship
A container ship (also called boxship or spelled containership) is a cargo ship that carries all of its load in truck-size intermodal containers, in a technique called containerization. Container ships are a common means of commercial intermoda ...
s are positioned throughout the world with enough equipment and supplies for a
marine expeditionary force to deploy for 30 days.
Doctrine
Two small manuals published during the 1930s established USMC doctrine in two areas. The ''
Small Wars Manual
The ''Small Wars Manual'' is a United States Marine Corps manual on tactics and strategies for engaging in certain types of military operations.
The Marine Corps' role in small wars has a long and complex history. During the early years of the 2 ...
'' laid the framework for Marine
counter-insurgency
Counterinsurgency (COIN) is "the totality of actions aimed at defeating irregular forces". The Oxford English Dictionary defines counterinsurgency as any "military or political action taken against the activities of guerrillas or revolutionar ...
operations from
Vietnam
Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making it ...
to
Iraq
Iraq,; ku, عێراق, translit=Êraq officially the Republic of Iraq, '; ku, کۆماری عێراق, translit=Komarî Êraq is a country in Western Asia. It is bordered by Turkey to Iraq–Turkey border, the north, Iran to Iran–Iraq ...
and
Afghanistan
Afghanistan, officially the Islamic Emirate of Afghanistan,; prs, امارت اسلامی افغانستان is a landlocked country located at the crossroads of Central Asia and South Asia. Referred to as the Heart of Asia, it is bord ...
while the ''Tentative Landing Operations Manual'' established the doctrine for the
amphibious operations of World War II. "''Operational Maneuver from the Sea''" was the doctrine of power projection in 2006.
History
Foundation and American Revolutionary War

The United States Marine Corps traces its roots to the
Continental Marines of 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 a major war of the American Revolution. Widely considered as the war that secured the independence of ...
, formed by Captain
Samuel Nicholas by a resolution of the
Second Continental Congress
The Second Continental Congress was a late-18th-century meeting of delegates from the Thirteen Colonies that united in support of the American Revolutionary War. The Congress was creating a new country it first named " United Colonies" and in ...
on 10 November 1775, to raise two
battalion
A battalion is a military unit, typically consisting of 300 to 1,200 soldiers commanded by a lieutenant colonel, and subdivided into a number of companies (usually each commanded by a major or a captain). In some countries, battalions are ...
s of marines. This date is celebrated as the
birthday of the Marine Corps. Nicholas was nominated to lead the Marines by
John Adams
John Adams (October 30, 1735 – July 4, 1826) was an American statesman, attorney, diplomat, writer, and Founding Fathers of the United States, Founding Father who served as the second president of the United States from 1797 to 1801. Befor ...
. By December 1775, Nicholas raised one battalion of 300 men by recruitment in his home city of Philadelphia.
In January 1776, the Marines went to sea under the command of Commodore
Esek Hopkins and in March undertook their first amphibious landing, the
Battle of Nassau in the Bahamas, occupying the British port of Nassau for two weeks.
On 3 January 1777, the Marines arrived at the
Battle of Princeton
The Battle of Princeton was a battle of the American Revolutionary War, fought near Princeton, New Jersey on January 3, 1777, and ending in a small victory for the Colonials. General Lord Cornwallis had left 1,400 British troops under the comm ...
attached to General
John Cadwalader's brigade, where they had been assigned by General
George Washington; by December 1776, Washington was retreating through New Jersey and, "in desperate need of veteran soldiers," had ordered Nicholas and the Marines to attach themselves to the
Continental Army. The
Battle of Princeton
The Battle of Princeton was a battle of the American Revolutionary War, fought near Princeton, New Jersey on January 3, 1777, and ending in a small victory for the Colonials. General Lord Cornwallis had left 1,400 British troops under the comm ...
, where the Marines along with General Cadwalader's brigade were personally rallied by Washington, was the first land combat engagement of the Marines; an estimated 130 marines were present at the battle.
At the end of the American Revolution, both the
Continental Navy
The Continental Navy was the navy of the United States during the American Revolutionary War and was founded October 13, 1775. The fleet cumulatively became relatively substantial through the efforts of the Continental Navy's patron John Adam ...
and Continental Marines were disbanded in April 1783. The institution was resurrected on 11 July 1798; in preparation for the
Quasi-War
The Quasi-War (french: Quasi-guerre) was an undeclared naval war fought from 1798 to 1800 between the United States and the French First Republic, primarily in the Caribbean and off the East Coast of the United States. The ability of Con ...
with
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan ar ...
, Congress created the United States Marine Corps. Marines had been enlisted by the
War Department as early as August 1797 for service in the newly-built
frigates authorized by the Congressional "Act to provide a Naval Armament" of 18 March 1794, which specified the numbers of marines to recruit for each frigate.
The Marines' most famous action of this period occurred during the
First Barbary War (1801–1805) against the
Barbary pirates, when
William Eaton and First Lieutenant
Presley O'Bannon led 8 marines and 500
mercenaries in an effort to capture
Tripoli
Tripoli or Tripolis may refer to:
Cities and other geographic units Greece
*Tripoli, Greece, the capital of Arcadia, Greece
*Tripolis (region of Arcadia), a district in ancient Arcadia, Greece
* Tripolis (Larisaia), an ancient Greek city in t ...
. Though they only reached
Derna, the action at Tripoli has been immortalized in the
Marines' Hymn and the
Mameluke sword carried by Marine officers.
War of 1812 and afterward

During the
War of 1812
The War of 1812 (18 June 1812 – 17 February 1815) was fought by the United States of America and its indigenous allies against the United Kingdom and its allies in British North America, with limited participation by Spain in Florida. It ...
, Marine detachments on Navy ships took part in some of the great frigate duels that characterized the war, which were the first and last engagements of the conflict. Their most significant contribution was holding the center of General
Andrew Jackson
Andrew Jackson (March 15, 1767 – June 8, 1845) was an American lawyer, planter, general, and statesman who served as the seventh president of the United States from 1829 to 1837. Before being elected to the presidency, he gained fame a ...
's defensive line at the 1815
Battle of New Orleans
The Battle of New Orleans was fought on January 8, 1815 between the British Army under Major General Sir Edward Pakenham and the United States Army under Brevet Major General Andrew Jackson, roughly 5 miles (8 km) southeast of the Fren ...
, the final major battle and one of the most one-sided engagements of the war. With widespread news of the battle and the
capture of HMS ''Cyane'', HMS ''Levant'' and
HMS ''Penguin'', the final engagements between British and U.S. forces, the Marines had gained a reputation as expert
marksmen, especially in defensive and ship-to-ship actions.
They played a large role in the 1813
defense of Sacket's Harbor, New York and
Norfolk and Portsmouth, Virginia, also taking part in the 1814
defense of Plattsburgh in the
Champlain Valley during one of the final British offensives along the Canadian-U.S. border. The
battle of Bladensburg, fought 24 August 1814, was one of the worst days for American arms, though a few units and individuals performed heroic service. Notable among them were Commodore Joshua Barney's 500 sailors and the 120 marines under Captain Samuel Miller USMC, who inflicted the bulk of British casualties and were the only effective American resistance during the battle. A final desperate Marine counter attack, with the fighting at close quarters, however was not enough; Barney and Miller's forces were overrun. In all of 114 marines, 11 were killed and 16 wounded. During the battle Captain Miller's arm was badly wounded, for his gallant service in action, Miller was brevetted to the rank of Major USMC.

After the war, the Marine Corps fell into a malaise that ended with the appointment of
Archibald Henderson as its fifth commandant in 1820. Under his tenure, the Corps took on expeditionary duties in the Caribbean, the
Gulf of Mexico
The Gulf of Mexico ( es, Golfo de México) is an ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of the United S ...
,
Key West, West Africa, the
Falkland Islands
The Falkland Islands (; es, Islas Malvinas, link=no ) is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and about from Cape Dubou ...
, and
Sumatra. Commandant Henderson is credited with thwarting President Jackson's attempts to combine and integrate the Marine Corps with the Army.
Instead, Congress passed the ''Act for the Better Organization of the Marine Corps'' in 1834, stipulating that the Corps was part of the Department of the Navy as a sister service to the Navy. This would be the first of many times that the independent existence of the Corps was challenged.
Commandant Henderson volunteered the Marines for service in the
Seminole Wars of 1835, personally leading nearly half of the entire Corps (two battalions) to war. A decade later, in the
Mexican–American War
The Mexican–American War, also known in the United States as the Mexican War and in Mexico as the (''United States intervention in Mexico''), was an armed conflict between the United States and Second Federal Republic of Mexico, Mexico f ...
(1846–1848), the Marines made their famed
assault on Chapultepec Palace in Mexico City, which would be later celebrated as the "Halls of Montezuma" in the Marines' Hymn. In fairness to the U.S. Army, most of the troops who made the final assault at the Halls of Montezuma were soldiers and not marines. The Americans forces were led by Army General
Winfield Scott
Winfield Scott (June 13, 1786May 29, 1866) was an American military commander and political candidate. He served as a general in the United States Army from 1814 to 1861, taking part in the War of 1812, the Mexican–American War, the early s ...
. Scott organized two storming parties of about 250 men each for 500 men total including 40 marines.
In the 1850s, the Marines engaged in service in Panama and Asia and were attached to Commodore
Matthew Perry's East India Squadron on its historic trip to the Far East.
American Civil War to World War I

The Marine Corps played a small role in the
Civil War
A civil war or intrastate war is a war between organized groups within the same state (or country).
The aim of one side may be to take control of the country or a region, to achieve independence for a region, or to change government polic ...
(1861–1865); their most prominent task was
blockade
A blockade is the act of actively preventing a country or region from receiving or sending out food, supplies, weapons, or communications, and sometimes people, by military force.
A blockade differs from an embargo or sanction, which ar ...
duty. As more and more states
seceded from the
Union, about a third of the Corps's officers left the United States to join the
Confederacy
Confederacy or confederate may refer to:
States or communities
* Confederate state or confederation, a union of sovereign groups or communities
* Confederate States of America, a confederation of secessionist American states that existed between ...
and form the
Confederate States Marine Corps, which ultimately played little part in the war. The battalion of recruits formed for the
First Battle of Bull Run
The First Battle of Bull Run (the name used by Union forces), also known as the Battle of First Manassascites 18,052 Confederate men and 37 guns engaged. McDowell's plan was to move westward in three columns and make a diversionary attack on ...
performed poorly, retreating with the rest of the Union forces.
Blockade duty included sea-based amphibious operations to secure forward bases. In late November 1861, Marines and sailors landed a reconnaissance in force from at Tybee Island, Georgia, to occupy the lighthouse and
Martello tower
Martello towers, sometimes known simply as Martellos, are small defensive forts that were built across the British Empire during the 19th century, from the time of the French Revolutionary Wars onwards. Most were coastal forts.
They stand u ...
on the northern end of the island. It would later be the Army base for
bombardment of Fort Pulaski. In April and May 1862, Marines participated in
the capture and occupation of New Orleans and the occupation of Baton Rouge, Louisiana, key events in the war that helped secure Union control of the lower
Mississippi River
The Mississippi River is the second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it ...
basin and denied the Confederacy a major port and naval base on the
Gulf Coast.
The remainder of the 19th century was marked by declining strength and introspection about the mission of the Marine Corps. The Navy's transition from
sail
A sail is a tensile structure—which is made from fabric or other membrane materials—that uses wind power to propel sailing craft, including sailing ships, sailboats, windsurfers, ice boats, and even sail-powered land vehicles. Sails ma ...
to
steam
Steam is a substance containing water in the gas phase, and sometimes also an aerosol of liquid water droplets, or air. This may occur due to evaporation or due to boiling, where heat is applied until water reaches the enthalpy of vaporizat ...
put into question the need for Marines on naval ships. Meanwhile, Marines served as a convenient resource for interventions and landings to protect American interests overseas. The Corps was involved in over 28 separate interventions in the 30 years from the end of the American Civil War to the end of 19th century. They were called upon to stem political and labor unrest within the United States.
Under Commandant
Jacob Zeilin's tenure, Marine customs and traditions took shape: the Corps adopted the
Marine Corps emblem on 19 November 1868. It was during this time that "The Marines' Hymn" was first heard. Around 1883, the Marines adopted their current motto "''
Semper fidelis''" (''Always Faithful'').
John Philip Sousa
John Philip Sousa ( ; November 6, 1854 – March 6, 1932) was an American composer and conductor of the late Romantic era known primarily for American military marches. He is known as "The March King" or the "American March King", to di ...
, the musician and composer, enlisted as a Marine apprentice at age 13, serving from 1867 until 1872, and again from 1880 to 1892 as the leader of the
Marine Band.
During the Spanish–American War (1898), Marines led American forces ashore in the Philippines, Cuba, and Puerto Rico, demonstrating their readiness for deployment. At Guantánamo Bay, Cuba, the Marines seized an Guantanamo Bay Naval Base, advanced naval base that remains in use today. Between 1899 and 1916, the Corps continued its record of participation in foreign expeditions, including the Philippine–American War, the Boxer Rebellion in China, Panama, the Cuban Pacifications, the Perdicaris affair, Perdicaris incident in Morocco, United States occupation of Veracruz, Veracruz, Santo Domingo, and the Banana Wars in United States occupation of Haiti, Haiti and United States occupation of Nicaragua, Nicaragua; the experiences gained in counter-insurgency and Guerrilla warfare, guerrilla operations during this period were consolidated into the ''Small Wars Manual''.
World War I

During
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...
, Marines served as a part of the American Expeditionary Forces, American Expeditionary Force under General John J. Pershing when American entry into World War I, America entered into the war on 6 April 1917. The Marine Corps had a deep pool of officers and non-commissioned officers with battle experience and thus experienced a large expansion. The U.S. Marine Corps entered the war with 511 officers and 13,214 enlisted personnel and by 11 November 1918 had reached a strength of 2,400 officers and 70,000 enlisted. African-Americans were entirely excluded from the Marine Corps during this conflict. Opha May Johnson was the first woman to enlist in the Marines; she joined the Marine Forces Reserve, Marine Corps Reserve in 1918 during World War I, officially becoming the first female Marine.
From then until the end of World War I, 305 women enlisted in the Corps. During the Battle of Belleau Wood in 1918, the Marines and U.S. media reported that Germans had nicknamed them ''Teufel Hunden,'' meaning "Devil Dogs" for their reputation as shock troops and marksmen at ranges up to 900 meters; there is no evidence of this in German records (as ''Teufelshunde'' would be the proper German phrase). Nevertheless, the name stuck in U.S. Marine lore.
Interwar period, Between the World Wars, the Marine Corps was headed by Commandant John A. Lejeune, and under his leadership, the Corps studied and developed amphibious techniques that would be of great use in World War II. Many officers, including Lieutenant Colonel Earl Hancock Ellis, Earl Hancock "Pete" Ellis, foresaw a war in the Pacific with Empire of Japan, Japan and undertook preparations for such a conflict. Through 1941, as the prospect of war grew, the Corps pushed urgently for joint amphibious exercises with the Army and acquired amphibious equipment that would prove of great use in the upcoming conflict.
World War II

In
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...
, the Marines performed a central role in the Pacific War, along with the U.S. Army. The battles of Guadalcanal campaign, Guadalcanal, Bougainville campaign, Bougainville, Battle of Tarawa, Tarawa, Second Battle of Guam, Guam, Battle of Tinian, Tinian, New Britain campaign, Cape Gloucester, Battle of Saipan, Saipan, Battle of Peleliu, Peleliu, Battle of Iwo Jima, Iwo Jima, and Battle of Okinawa, Okinawa saw fierce fighting between marines and the Imperial Japanese Army. Some 600,000 Americans served in the U.S. Marine Corps in World War II.
The Battle of Iwo Jima, which began on 19 February 1945, was arguably the most famous Marine engagement of the war. The Japanese had learned from their defeats in the Mariana and Palau Islands campaign, Marianas Campaign and prepared many fortified positions on the island including Pillbox (military), pillboxes and network of tunnels. The Japanese put up fierce resistance, but American forces Raising the Flag on Iwo Jima, reached the summit of Mount Suribachi on 23 February. The mission was accomplished with high losses of 26,000 American casualties and 22,000 Japanese.
The Marines played a comparatively minor role in the European theatre of World War II, European theater. Nonetheless, they did continue to provide security detachments to U.S. embassies and ships, contributed personnel to small Special operations, special ops teams dropped into Wehrmacht, Nazi-occupied Europe as part of Office of Strategic Services (OSS, the precursor to the CIA) missions, and acted as staff planners and trainers for U.S. Army amphibious operations, including the Normandy landings. By the end of the war, the Corps had expanded from two brigades to six division (military), divisions, five Wing (military unit), air wings, and supporting troops, totaling about 485,000 marines. In addition, 20 Marine defense battalions, defense battalions and a paramarines, parachute battalion were raised. N