The
United States of America
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territo ...
was created on July 4, 1776, with the
U.S. Declaration of Independence
The United States Declaration of Independence, formally The unanimous Declaration of the thirteen States of America, is the pronouncement and founding document adopted by the Second Continental Congress meeting at Pennsylvania State House (l ...
of
thirteen British colonies
The Thirteen Colonies, also known as the Thirteen British Colonies, the Thirteen American Colonies, or later as the United Colonies, were a group of British colonies on the Atlantic coast of North America. Founded in the 17th and 18th centuri ...
in
North America. In the
Lee Resolution
The Lee Resolution (also known as "The Resolution for Independence") was the formal assertion passed by the Second Continental Congress on July 2, 1776 which resolved that the Thirteen Colonies in America (at the time referred to as United Colo ...
two days prior, the colonies resolved that they were free and independent states. The union was formalized in the
Articles of Confederation, which
came into force
In law, coming into force or entry into force (also called commencement) is the process by which legislation, regulations, treaties and other legal instruments come to have legal force and effect. The term is closely related to the date of this t ...
on March 1, 1781, after being ratified by all 13 states. Their independence was recognized by
Great Britain
Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It i ...
in the
Treaty of Paris Treaty of Paris may refer to one of many treaties signed in Paris, France:
Treaties
1200s and 1300s
* Treaty of Paris (1229), which ended the Albigensian Crusade
* Treaty of Paris (1259), between Henry III of England and Louis IX of France
* Trea ...
of 1783, which concluded 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 t ...
. This effectively doubled the size of the colonies, now able to stretch west past the
Proclamation Line to the
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 fl ...
. This land was organized into territories and then states, though there remained some conflict with the sea-to-sea grants claimed by some of the original colonies. In time, these grants were
ceded
The act of cession is the assignment of property to another entity. In international law it commonly refers to land transferred by treaty. Ballentine's Law Dictionary defines cession as "a surrender; a giving up; a relinquishment of jurisdictio ...
to the federal government.
The first great expansion of the country came with the
Louisiana Purchase
The Louisiana Purchase (french: Vente de la Louisiane, translation=Sale of Louisiana) was the acquisition of the territory of Louisiana by the United States from the French First Republic in 1803. In return for fifteen million dollars, or app ...
of 1803, which doubled the country's territory, although the southeastern border with
Spanish Florida was the subject of much dispute until it and Spanish claims to the
Oregon Country were ceded to the US in 1821. The Oregon Country gave the United States access to the
Pacific Ocean
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 definition, to Antarctica) in the south, and is bounded by the contin ...
, though it was shared for a time with the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...
.
The annexation of the
Republic of Texas in 1845 led directly to 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 Mexico from 1846 to 1848. It followed the 1 ...
, after which the victorious United States obtained the northern half of
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
's territory, including what was quickly made the state of
California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...
.
However, as the development of the country moved west, the question of
slavery
Slavery and enslavement are both the state and the condition of being a slave—someone forbidden to quit one's service for an enslaver, and who is treated by the enslaver as property. Slavery typically involves slaves being made to perf ...
became more important, with vigorous debate over whether the new territories would allow slavery and events such as the
Missouri Compromise
The Missouri Compromise was a federal legislation of the United States that balanced desires of northern states to prevent expansion of slavery in the country with those of southern states to expand it. It admitted Missouri as a slave state and ...
and
Bleeding Kansas
Bleeding Kansas, Bloody Kansas, or the Border War was a series of violent civil confrontations in Kansas Territory, and to a lesser extent in western Missouri, between 1854 and 1859. It emerged from a political and ideological debate over the ...
. This came to a head in 1860 and 1861, when the governments of the southern states proclaimed their secession from the country and formed the
Confederate States of America
The Confederate States of America (CSA), commonly referred to as the Confederate States or the Confederacy was an unrecognized breakaway republic in the Southern United States that existed from February 8, 1861, to May 9, 1865. The Confeder ...
. The
American Civil War
The American Civil War (April 12, 1861 – May 26, 1865; also known by other names) was a civil war in the United States. It was fought between the Union ("the North") and the Confederacy ("the South"), the latter formed by states ...
led to the defeat of the Confederacy in 1865 and the eventual readmission of the states to the
United States Congress
The United States Congress is the legislature of the federal government of the United States. It is bicameral, composed of a lower body, the House of Representatives, and an upper body, the Senate. It meets in the U.S. Capitol in Washing ...
. The cultural endeavor and pursuit of
manifest destiny provided a strong impetus for westward expansion in the 19th century.
The country began expanding beyond North America in 1856 with the passage of the
Guano Islands Act
The Guano Islands Act (, enacted August 18, 1856, codified at §§ 1411-1419) is a United States federal law passed by the U.S. Congress that enables citizens of the United States to take possession, in the name of the United States, of unclai ...
, causing many small and uninhabited, but economically important, islands in the Pacific Ocean and
Caribbean Sea
The Caribbean Sea ( es, Mar Caribe; french: Mer des Caraïbes; ht, Lanmè Karayib; jam, Kiaribiyan Sii; nl, Caraïbische Zee; pap, Laman Karibe) is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. It is bounded by Mexico ...
to be claimed.
Most of these claims were eventually abandoned, largely due to competing claims from other countries. The Pacific expansion culminated in the
annexation of Hawaii in 1898, after the
overthrow of its government five years previously.
Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S. ...
, the last major acquisition in North America, was
purchased from
Russia
Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...
in 1867.
Support for the independence of
Cuba
Cuba ( , ), officially the Republic of Cuba ( es, República de Cuba, links=no ), is an island country comprising the island of Cuba, as well as Isla de la Juventud and several minor archipelagos. Cuba is located where the northern Caribbea ...
from the
Spanish Empire
The Spanish Empire ( es, link=no, Imperio español), also known as the Hispanic Monarchy ( es, link=no, Monarquía Hispánica) or the Catholic Monarchy ( es, link=no, Monarquía Católica) was a colonial empire governed by Spain and its prede ...
, and the sinking of the
USS Maine
Four ships of the United States Navy have borne the name USS ''Maine'', named for the 23rd state:
* , was a battleship whose 1898 sinking precipitated the Spanish–American War.
* , launched in 1901, was the lead ship of her class of battleships ...
, led to the
Spanish–American War
, partof = the Philippine Revolution, the decolonization of the Americas, and the Cuban War of Independence
, image = Collage infobox for Spanish-American War.jpg
, image_size = 300px
, caption = (cloc ...
in 1898, in which the United States gained
Guam
Guam (; ch, Guåhan ) is an organized, unincorporated territory of the United States in the Micronesia subregion of the western Pacific Ocean. It is the westernmost point and territory of the United States (reckoned from the geographic cent ...
,
Puerto Rico
Puerto Rico (; abbreviated PR; tnq, Boriken, ''Borinquen''), officially the Commonwealth of Puerto Rico ( es, link=yes, Estado Libre Asociado de Puerto Rico, lit=Free Associated State of Puerto Rico), is a Caribbean island and unincorporated ...
, and the
Philippines
The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no),
* bik, Republika kan Filipinas
* ceb, Republika sa Pilipinas
* cbk, República de Filipinas
* hil, Republ ...
, and occupied Cuba for several years.
American Samoa
American Samoa ( sm, Amerika Sāmoa, ; also ' or ') is an unincorporated territory of the United States located in the South Pacific Ocean, southeast of the island country of Samoa. Its location is centered on . It is east of the Internationa ...
was acquired by the United States in 1900 after the end of the
Second Samoan Civil War
The Second Samoan Civil War was a conflict that reached a head in 1898 when Germany, the United Kingdom, and the United States were locked in dispute over who should have control over the Samoan island chain, located in the South Pacific Ocea ...
. The United States purchased the
U.S. Virgin Islands from Denmark in 1917. Guam and Puerto Rico remain territories; the Philippines became independent in 1946, after being a major 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 vast majority of the world's countries—including all of the great powers—forming two opposing ...
. Following the war,
many islands were
entrusted to the U.S. by the
United Nations
The United Nations (UN) is an intergovernmental organization whose stated purposes are to maintain international peace and security, develop friendly relations among nations, achieve international cooperation, and be a centre for harmoniz ...
,
and while the
Northern Mariana Islands
The Northern Mariana Islands, officially the Commonwealth of the Northern Mariana Islands (CNMI; ch, Sankattan Siha Na Islas Mariånas; cal, Commonwealth Téél Falúw kka Efáng llól Marianas), is an unincorporated territory and commonw ...
remain a U.S. territory, the
Marshall Islands
The Marshall Islands ( mh, Ṃajeḷ), officially the Republic of the Marshall Islands ( mh, Aolepān Aorōkin Ṃajeḷ),'' () is an independent island country and microstate near the Equator in the Pacific Ocean, slightly west of the Intern ...
,
Federated States of Micronesia
The Federated States of Micronesia (; abbreviated FSM) is an island country in Oceania. It consists of four states from west to east, Yap, Chuuk, Pohnpei and Kosraethat are spread across the western Pacific. Together, the states comprise a ...
, and
Palau
Palau,, officially the Republic of Palau and historically ''Belau'', ''Palaos'' or ''Pelew'', is an island country and microstate in the western Pacific. The nation has approximately 340 islands and connects the western chain of the ...
emerged from the trust territory as independent nations. The last major international change was the acquisition in 1904, and return to
Panama
Panama ( , ; es, link=no, Panamá ), officially the Republic of Panama ( es, República de Panamá), is a transcontinental country spanning the southern part of North America and the northern part of South America. It is bordered by Co ...
in 1979, of the
Panama Canal Zone, an unincorporated US territory which controlled the
Panama Canal
The Panama Canal ( es, Canal de Panamá, link=no) is an artificial waterway in Panama that connects the Atlantic Ocean with the Pacific Ocean and divides North and South America. The canal cuts across the Isthmus of Panama and is a condui ...
. The final cession of formal control over the region was made to Panama in 1999.
Regarding internal borders, while territories could shift wildly in size, once established states have generally retained their initial borders. Only four states—
Maine
Maine () is a state in the New England and Northeastern regions of the United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Canadian provinces of New Brunswick and Quebec to the northeast and ...
,
Kentucky
Kentucky ( , ), officially the Commonwealth of Kentucky, is a state in the Southeastern region of the United States and one of the states of the Upper South. It borders Illinois, Indiana, and Ohio to the north; West Virginia and Virginia ...
,
Vermont
Vermont () is a state in the northeast New England region of the United States. Vermont is bordered by the states of Massachusetts to the south, New Hampshire to the east, and New York to the west, and the Canadian province of Quebec to ...
, and
West Virginia
West Virginia is a state in the Appalachian, Mid-Atlantic and Southeastern regions of the United States.The Census Bureau and the Association of American Geographers classify West Virginia as part of the Southern United States while the B ...
—have been created from land claimed by another state; all of the others were created from territories or directly from acquisitions. Four states—
Louisiana
Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is borde ...
,
Missouri
Missouri is a state in the Midwestern region of the United States. Ranking 21st in land area, it is bordered by eight states (tied for the most with Tennessee): Iowa to the north, Illinois, Kentucky and Tennessee to the east, Arkansas t ...
,
Nevada
Nevada ( ; ) is a state in the Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the 7th-most extensive, ...
, and
Pennsylvania
Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...
—have expanded significantly by acquiring additional federal territory after their initial
admission to the Union
Admission may refer to:
Arts and media
* "Admissions" (''CSI: NY''), an episode of ''CSI: NY''
* ''Admissions'' (film), a 2011 short film starring James Cromwell
* ''Admission'' (film), a 2013 comedy film
* ''Admission'', a 2019 album by Florida s ...
. The
last state of the
contiguous United States, commonly called the "lower 48", was admitted in 1912; the
fiftieth and most recent state was admitted in 1959.
Legend for maps
::::Key to map colors
::::
::::
::::
::::
1776–1784 (American Revolution)
1784–1803 (Organization of territory)
1803–1818 (Purchase of Louisiana)
1819–1845 (Northwest expansion)
1845–1860 (Southwest expansion)
1860–1865 (Civil War)
1866–1897 (Reconstruction and western statehood)
1898–1945 (Pacific and Caribbean expansion)
1946–present (Decolonization)
Bancos along the Rio Grande
The
Banco Convention of 1905
The Banco Convention of 1905, between the United States and Mexico, was negotiated and signed in 1905 and ratified by both nations in 1907. It resulted in 247 exchanges of bancos (land surrounded by bends in the river that became segregated by a ...
between the United States and
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
allowed, in the event of sudden changes in the course of the
Rio Grande (as by flooding), for the border to be altered to follow the new course. The sudden changes often created ''bancos'' (land surrounded by bends in the river that became segregated from either country by a cutoff, often due to rapid accretion or avulsion of the alluvial channel), especially in the Lower Rio Grande Valley. When these bancos are created, the
International Boundary and Water Commission
The International Boundary and Water Commission ( es, links=no, Comisión Internacional de Límites y Aguas) is an international body created by the United States and Mexico in 1889 to apply the rules for determining the location of their intern ...
investigates if land previously belonging to the United States or
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
is to be considered on the other side of the border. In all cases of these adjustments along the Rio Grande under the 1905 convention, which occurred on 37 different dates from 1910 to 1976, the transferred land was minuscule (ranging from one to 646 acres) and uninhabited.
See also
*
Geography of the United States
The term 'United States', when used in the geographical sense, refers to the contiguous United States, the state of Alaska, the island state of Hawaii, the five insular territories of Puerto Rico, Northern Mariana Islands, U.S. Virgin Islan ...
*
Territories of the United States
Territories of the United States are sub-national administrative divisions overseen by the federal government of the United States. The various American territories differ from the U.S. states and tribal reservations as they are not sove ...
*
Historic regions of the United States
The territory of the United States and its overseas possessions has evolved over time, from the colonial era to the present day. It includes formally organized territories, proposed and failed states, unrecognized breakaway states, internationa ...
*
American frontier
*
List of U.S. state partition proposals
Numerous state partition proposals have been put forward since the 1776 establishment of the United States that would partition an existing U.S. state or states so that a particular region might either join another state or create a new state ...
*
List of U.S. states by date of admission to the Union
*
Movements for the annexation of Canada to the United States
From the independence of the United States until today, various movements within Canada have campaigned in favour of U.S. annexation of parts or all of Canada. Historical studies have focused on numerous small-scale movements which are helpful in c ...
*
National Atlas of the United States
The ''National Atlas of the United States'' was an atlas published by the United States Department of the Interior from 1874 to 1997.
Older editions were printed, but the most recent edition was available online. Since it is a publication of t ...
*
Ostend Manifesto
The Ostend Manifesto, also known as the Ostend Circular, was a document written in 1854 that described the rationale for the United States to purchase Cuba from Spain while implying that the U.S. should declare war if Spain refused. Cuba's annex ...
(annexation of Cuba)
*
List of territorial claims and designations in Colorado
The area currently occupied by the U.S. State of Colorado has undergone numerous changes in occupancy, territorial claims, and political designations. Paleoamericans entered the region about 11,500 BCE,Cassells, E. Steve. (1997). ''The Ar ...
*
Territorial evolution of Arizona
A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal.
In international politics, a territory is usually either the total area from which a state may extract power resources or a ...
*
Territorial evolution of California
240px, Spanish period: An enlargeable map of the United States after the Treaty of Paris in 1783.
The following timeline traces the territorial evolution of California, the thirty-first state admitted to the United States of America, in ...
*
Territorial evolution of Idaho
The following chronology traces the territorial evolution of the U.S. State of Idaho.
Timeline
*Historical territorial claims of Spain in the present State of Idaho:
** Gran Cuenca, 1776–1821
** Adams-Onis Treaty of 1819
*Historic ...
*
Territorial evolution of Montana
The following chronology traces the territorial evolution of the U.S. State of Montana.
Timeline
*Historical territorial claims of the United Kingdom in the present State of Montana:
**Rupert's Land, 1670–1870
*** Anglo-Americ ...
*
Territorial evolution of Nevada
*
Territorial evolution of New Mexico
The area currently occupied by the U.S. State of New Mexico has undergone numerous changes in occupancy and territorial claims and designations. This geographic chronology traces the territorial evolution of New Mexico.
__TOC__
Timeline
*Histori ...
*
Territorial evolution of North Dakota
*
Territorial evolution of Oregon
An enlargeable map of the United States after the Treaty of Paris in 1789
The following outline traces the territorial evolution of the U.S. state of Oregon.
Outline
*Historical territorial claims of Spain in the present state of Oregon:
...
*
Territorial evolution of South Dakota 240px, An enlargeable map of the United States after the Treaty of Paris in 1789
The following outline traces the territorial evolution of the U.S. State of South Dakota.
Outline
240px, An enlargeable map of the United States after the Louisi ...
*
Territorial evolution of Utah
The following timeline traces the territorial evolution of the U.S. State of Utah.
Timeline
*Historical territorial claims of Spain in the present State of Utah:
**Nueva Vizcaya, 1562–1821
**Santa Fé de Nuevo Méjico, 1598–1821
* ...
*
Territorial evolution of Washington
The following outline traces the territorial evolution of the U.S. State of Washington.
Outline
*Historical international territory in the present State of Washington:
** Oregon Country, 1818-1846
*** Anglo-American Convention of 1818
***P ...
*
Territorial evolution of Wyoming
*
Territories of the United States on stamps
Territories of the United States on stamps discusses commemorative postal issues devoted to lands that have been ceded to the nation or purchased by treaty in conjunction with both war and peace. Thirteen states have been created from colonial t ...
*
List of U.S.–Native American treaties, which indicates tribal land cessions
Notes
References
Further reading
*
*
*
{{featured list
Border-related lists
Borders of the United States
Borders of U.S. states
Former regions and territories of the United States
History of United States expansionism
History of colonialism