National Atlas map of United States territorial acquisitions
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, international and interstate purchases, cessions, and land grants, and historical military departments and administrative districts. The last section lists informal regions from American vernacular geography known by popular nicknames and linked by geographical, cultural, or economic similarities, some of which are still in use today.
Map showing mid 17th century claims and land grant boundaries. Some colonies seen here are: Nova Scotia (NSc), Territory of Sagadahock (TS), First Province of Maine (Me), New Hampshire (NH), Plymouth (PC), Massachusetts Bay (MBC), New Netherland (NN), New Sweden (NSw), and Lord Baltimore's Land (Md; Maryland)New World settlements of The Netherlands, collectively called New Netherland
The Massachusetts Bay ColonyFrench settlements and forts in the so-called Illinois Country, 1763, which encompassed parts of the modern day states of Illinois, Missouri, Indiana and Kentucky)A 1775 map of the German Coast, a historical region of present-day Louisiana located above New Orleans on the eastern bank of the Mississippi RiverVandalia was the name of a proposed British colony located south of the Ohio River, primarily in what is now the U.S. states of West Virginia and eastern KentuckyA proposal for the creation of Westsylvania was largely deterred by the Revolutionary War
Map showing North American territorial boundaries leading up to the American Revolution and the founding of the United States: British claims are indicated in red and pink, while Spanish claims are in orange and yellow.
The Oregon Country. The dispute over Oregon, between Britain and the U.S., led to an uneasy, parallel governing of the territory for almost 30 years.Seward's Folly. The controversial purchase of Alaska from Russia in 1867 turned out to be a great deal for the U.S. when the area proved to contain a treasure trove of natural resources.The Baton Rouge and Mobile Districts of Spanish West Florida, claimed by the United States, spanned parts of three later states. The Spanish province also included part of the present-day state of Florida.
Texas annexation; annexed from Mexico in 1846, including most of present-day Texas and parts of Oklahoma, Colorado, Wyoming and No Man's Land; disputed with Mexico until the end of the Mexican–American War in 1848
Progression of the two territorial governments, 1819–1836: Indian Territory is in teal; Arkansas is in dark green; western portion of Lovely's Purchase is in light green (to Indian Territory, 1828)Indiana lands acquired through treaties
Interstate, territorial, and federal cessions[edit]
The first state cessions. The 13 original states ceded their western claims to the federal government, allowing for the creation of the country's first western territories and states.
The following are state cessions made during the building of the U.S.
The Delaware Wedge, dispute with Pennsylvania settled in 1921; now a part of the state of Delaware.
District of Columbia retrocession; the return to Virginia of the District of Columbia lands which Virginia had originally ceded for its creation, 1847.
The Northwest Territory was ceded by Great Britain to the United States at the end of the American Revolutionary War. Britain irrevocably ceded all claims to the territory in the 1814 Treaty of Ghent.United States territorial expansion since 1803, maps by William R. Shepherd (1923)Census Bureau map depicting territorial acquisitions and effective dates of statehood
Territory of Missouri (1812–1821) became the State of Missouri and Unorganized Territory (the eastern part of which was attached to the Territory of Michigan in 1834).
Territory of Minnesota (1849–1858) preceded by unorganized territory of the original Northwest Territory (remnant of former Wisconsin Territory) and original Louisiana Purchase; split into the State of Minnesota and unorganized territory of the original Louisiana Purchase.
Territory of Kansas (1854–1861) preceded by unorganized territory of the original Louisiana Purchase. Part became the modern State of Kansas; the western part became part of the Colorado Territory.
Territory of Nebraska (1854–1867) preceded by unorganized territory of the original Louisiana Purchase; split into the State of Nebraska, the Dakota Territory, additions to the Idaho Territory and additions to the Colorado Territory.
Territory of Idaho (1863–1890) preceded by parts of the territories of Washington, Dakota, and Nebraska; became the State of Idaho, the Montana Territory, additions to the Dakota Territory and additions to the Wyoming Territory.
Internal land grants, cessions, districts, departments, claims and settlements[edit]
The Ohio Country, indicating battle sites between settlers and Native American Tribes, 1775–1794
The following are land grants, cessions, defined districts (official or otherwise) or named settlements made within an area that was already part of a U.S. state or territory that did not involve international treaties or Native American cessions or land purchases.
District of Louisiana; Missouri, Kansas, Iowa, Nebraska, Minnesota, North and South Dakota, Montana, Arkansas, Oklahoma, Colorado, Wyoming; renamed Missouri Territory in 1812.
These entities were sometimes the only governmental authority in the listed areas, although they often co-existed with civil governments in scarcely populated states and territories. Civilian administered "military" tracts, districts, departments, etc., will be listed elsewhere.
Department of the Missouri (1861–1865) Missouri, Arkansas, Illinois, part of Kentucky, and later Kansas; re-configured in 1865 as part of the Division of the Missouri.
District of California (headquarters at San Francisco, co-located with Department of the Pacific). Independent command from Department from (July 1, 1864 – July 27, 1865); those parts of California not in other districts.
The Department of California (1858–1861) comprised the southern part of the Department of the Pacific: California, Nevada, and southern part of Oregon Territory; merged into the Department of the Pacific as the District of California.
The Department of Oregon (1858–1861) comprised the northern part of the Department of the Pacific: Washington Territory and Oregon Territory.
Trans-Mississippi (or Trans-Mississippi Department; CSA) (1862–1865). Formerly "Military Dept. 2"; Missouri, Arkansas, Texas, Indian Territory (now Oklahoma), Kansas, and Louisiana west of the Mississippi River.
Department of the West (1853–1861): all U.S. lands between the Mississippi River and the Military District of the Pacific not included in other Districts or Departments.
Retroceded possessions and overseas territories[edit]
The Panama Canal Zone was once a territory of the United States
Kansas Territory (1854–1861) had two different governments in different cities, pro-slavery and anti-slavery, each claiming to be the real, lawful government of the entire territory. Since Kansas entered the union as a free state in 1861, there has only been one capital, Topeka, Kansas. It entered as a free state in 1861 because the entire pro-slavery block in Congress, which would not have allowed this, had left to become the Confederacy.
Animated map of secession and repatriation of the Confederacy, 1860–1870
These are functioning governments created as a result of the attempted secession of the Confederacy during the American Civil War (1861–1865). Some were enclaves within enemy-held territories:
Belts are loosely defined sub-regions found throughout the United States that are named for a perceived commonality among the included areas, which is often related to the region's economy or climate.
^Heidler, David Stephen; Heidler, Jeanne T.; Coles, David J.; Encyclopedia of the American Civil War: A Political, Social, and Military History; W. W. Norton & Company; New York; 2000; p. 590.