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 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)
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
The Northwest Territory was a large and (at times) ill-defined territory ceded by Great Britain to the U.S. at the end of the Revolutionary War. British troops still occupied parts of the area well past 1800.
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 Minnesota (1849–1858) preceded (mostly) by unorganized territory of the 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.
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.
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.
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.
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.
The proposed State of Superior. The red areas show the counties of the Upper Peninsula that are generally accepted as being part of the proposed state. The pink areas show the counties of the "expanded" proposal.
The failed State of Lincoln, with its proposed 1868 boundaries
These are state or territorial proposals actually brought to either a congressional, legislative or popular vote, but which never became a functioning entity: