User:New Years Paniponi Dash/Territorial evolution of the United States

This is a list of the evolution of the borders of the United States. This lists each change to the internal and external borders of the country, as well as status and name changes. It also shows the surrounding areas that eventually became part of the United States. Each situation has a map, to show what the specific makeup of the country was at any given time.

After achieving independence with the Treaty of Paris, the United States expanded westward, enlarging its borders seven times, with two major border adjustments, one each with colonies of the United Kingdom and Spain, and several small disputes. The original thirteen states grew into fifty states, most of which began as incorporated territories. The general pattern seen in this is of territorial expansion, carving of organized territories from the newly acquired land, modification of the borders of these territories, and eventual statehood. Only two states, Nevada and Missouri, grew appreciably after statehood, and four, Massachusetts, North Carolina, Texas, and Virginia, lost land, in each case to form new states.

Notes

• This article does not include unincorporated territories and countries under free association. The fundamental difference between unincorporated and incorporated territories is that incorporated territories are considered to forever be under the jurisdiction of the United States Constitution, whereas it is possible for unincorporated territories to become independent. These are:
  • Nations under Compacts of Free Association: Marshall Islands, Federated States of Micronesia, Palau.
  • Unincorporated, organized territories: Guam, United States Virgin Islands.
  • Commonwealths, another form of unincorporated and organized territory: Northern Mariana Islands, Puerto Rico (This is different from the term commonwealth used by some states.)
  • American Samoa is unorganized, but has a constitution and self-government, making it functionally very similar to an organized territory.
  • The United States Minor Outlying Islands, which are uninhabited, unorganized, and except for Palmyra Atoll, unincorporated.
  • The former unincorporated territories of the Line Islands, Panama Canal Zone, the Commonwealth of the Philippines, and the Phoenix Islands.
  • The Trust Territory of the Pacific Islands, a United Nations trusteeship granted to the United States following World War II. It has since dissolved, becoming the Marshall Islands, Federated States of Micronesia, the Northern Mariana Islands, and Palau.
• "Unorganized territory" is not a name; it simply means Congress has not passed an organic act for the territory. In most situations, the purpose of unorganized territory was to act as land for Native American settlement. Later, the last unorganized territory in the country was indeed referred to as "Indian Territory", though this is not an official name. The last territories acquired by the United States, Alaska, Hawaii, and the Mexican Cession, began unorganized, but not as land set aside for Native Americans, but simply because they had not been organized yet.
• Dotted lines on the borders mean that region is part of a country not fully shown on the map, since it's confined to the present-day borders of the United States. An exception is Oregon Country, which was shared land which extended beyond the area of the map.
• Some territorial disputes and borders from early in the United States' history are unclear. For example, the border between West Florida and East Florida seems unclear. For the purposes of simplicity, this article uses the original border, the Apalachicola River, even though later maps tended to move it west to the Perdido River. This is partly because the Organic Act for Florida specified that it included parts of both West and East Florida; if the border were the Perdido River, then Florida Territory would not have included any of West Florida, it having already been divided among Louisiana, Mississippi, and Alabama.
• Several very small changes are included in the list but not included in the maps.

1. The switch of two extra counties from Virginia to West Virginia at the end of the American Civil War.
2. The Alaska Boundary Dispute, since it arose from a total lack of surveying, rather than a dispute over the surveyed lines; it would also appear quite small on the map.
3. The dispute over The Wedge, a square mile of land claimed by Pennsylvania and Delaware.
4. When the Dakota Territory was created, it also included land south of 43° N and north of the Keya Paha and Niobrara rivers. This was transferred to the state of Nebraska on March 28 1882.[1]
5. The two small adjustments to Indiana Territory.
6. Various disputes along the Rio Grande with Mexico.

18th century

March 4 1789

The United States Constitution came into effect, forming the new nation. Note that the states ratified at different times, but to simplify the map, the final result is shown here.

The United States achieved independence from the Kingdom of Great Britain with the Treaty of Paris on September 3 1783, which established that the thirteen colonies were sovereign and independent states. The borders were established by Article 2 of the treaty, but with a couple of issues. First, it stated that the border would run west from the Lake of the Woods to the Mississippi River - at the time, it was not known that the headwaters of the Mississippi lay south of such a line, so the border has since been taken to run south from the lake to the river.

Some peculiarities to point out to those familiar only with the current borders: Many states had sea-to-sea grants from the British crown that they would not give up easily, so prior to this date, they ceded this land to the federal government in exchange for their Revolutionary War debts. However, Georgia did not do so until much later, and Connecticut ceded most land but kept its Western Reserve. Virginia ceded its claim to the territory north and west of the Ohio River, and this land became unorganized territory. North Carolina also ceded its claim to its western counties, but this was not officially accepted by Congress until 1790. New York ceded its claim on the Erie Triangle to the federal government. At this point in history, all of the states except for Georgia and Virginia were at their present-day borders, except for some of the minor issues mentioned above.

West Florida claimed a border further north than what the United States said it had. Its border had been 31° north when Spain ceded it to the United Kingdom. The British later moved its border north to 32°38' latitude, but when Spanish Florida was ceded back to Spain in the Treaty of Paris, the British cited the original border at the 31st parallel, but Spain continued to claim the higher border. Also, the borders at the northern area of the Maine District of Massachusetts and the area northwest of Lake Superior remained disputed.

The Wedge, disputed since the 17th century, remained a point of contention between Delaware and Pennsylvania.

The Vermont Republic was a complex matter, with areas being claimed by New York and New Hampshire, but it existed as a de facto unrecognized independent nation.

August 7 1789

The United States Congress affirmed the organization of the Territory North West of the Ohio River, or Northwest Territory, under the terms of the Northwest Ordinance. Northwest Territory consisted of present-day Illinois, Indiana, Michigan, northeastern Minnesota, most of Ohio, and Wisconsin. The Northwest Territory had previously been organized under the Articles of Confederation on July 13 1787, and was slightly modified under the new Constitution.

<nowiki>[[Image:United States 1790-04-1790-05.png|250px|right]]</nowiki>;April 2 1790 Congress accepts North Carolina's cession of its western counties, which had initially been ceded on December 22 1789. The land became unorganized territory.

[[Image:United States 1790-05-1791-03.png|250px|right]]

May 26 1790

The Southwest Ordinance organized the Territory South of the Ohio River, or Southwest Territory, which corresponded to present-day Tennessee.

[[Image:United States 1791-03-1791-09.png|250px|right]]

March 4 1791

The Vermont Republic, which had portions claimed by New York and New Hampshire and, while unrecognized by the United States, was a de facto independent country, was admitted as the 14th state, Vermont.

[[Image:United States 1791-09-1792-03.png|250px|right]]

September 9 1791

The District of Columbia, the nation's federal district, was formed from land granted by Maryland and Virginia; the Virginia portion would be returned in 1847.

[[Image:United States 1792-03-1792-06.png|250px|right]]

March 3 1792

The federal government sold the Erie Triangle to Pennsylvania.

[[Image:United States 1792-06-1795.png|250px|right]]

June 1 1792

The western counties of Virginia beyond the Appalachian Mountains were split off and admitted as the 15th state, Kentucky.

[[Image:United States 1795-1796.png|250px|right]]

August 2 1796

Pinckney's Treaty, also known as the Treaty of San Lorenzo, settles the northern border of West Florida as the 31st parallel.

[[Image:United States 1796-1798.png|250px|right]]

June 1 1796

The Southwest Territory was admitted as the 16th state, Tennessee.

[[Image:United States 1798-1800-07-04.png|250px|right]]

May 7 1798

Due to the Yazoo Land Fraud, an act was signed by President John Adams, authorizing him to appoint commissioners to negotiate with Georgia about ceding its western land. The act created Mississippi Territory in the region ceded by West Florida, corresponding to roughly the southern third of present-day Mississippi and Alabama except their panhandles, which were part of West Florida.

1800s

[[Image:United States 1800-07-04-1800-07-10.png|250px|right]]

July 4 1800

Indiana Territory was formed from the western portion of Northwest Territory. It corresponded to present-day Illinois, Indiana, northeastern Minnesota, and Wisconsin, as well as the western half of the Lower Peninsula of Michigan and all but the eastern tip of the Upper Peninsula. Northwest Territory was left with only most of Ohio and the rest of Michigan.

[[Image:United States 1800-07-10-1802.png|250px|right]]

July 10 1800

Connecticut ceded its Western Reserve to the federal government, which made it part of Northwest Territory, and is the northeastern part of present-day Ohio.

[[Image:United States 1802-1803-03.png|250px|right]]

April 26 1802

Georgia finally ceded its western claims, the Yazoo Lands, to the federal government, where it became unorganized land. Also, on October 1 1800, the Third Treaty of San Ildefonso transferred the colony of Louisiana from Spain to France.

[[Image:United States 1803-03-1803-04.png|250px|right]]

March 1 1803

The southeastern portion of Northwest Territory was admitted as the 17th state, Ohio. The remainder of Northwest Territory was transferred to Indiana Territory.

[[Image:United States 1803-04-1804-03.png|250px|right]]

April 30 1803

The Louisiana Purchase was made, expanding the United States west of the Mississippi River. There was a dispute with West Florida over how much land east of the Mississippi River it included. The purchase extended slightly north of the modern borders, as it was defined only as the watershed of the Mississippi River. The purchase consisted of the whole of present-day Arkansas, Kansas, Iowa, Missouri, Nebraska, and Oklahoma, and portions of Colorado, Louisiana, Minnesota, Montana, New Mexico, North Dakota, South Dakota, Texas and Wyoming. It also included the southernmost portions of the present-day Canadian provinces of Alberta, Manitoba, and Saskatchewan.

[[Image:United States 1804-03-1804-10.png|250px|right]]

March 27 1804

The unorganized land ceded by Georgia was added to Mississippi Territory, consisting of the whole of present-day Mississippi and Alabama, minus their panhandles which were still part of West Florida.

[[Image:United States 1804-10-1805-01.png|250px|right]]

October 1 1804

The Louisiana Purchase was split into the District of Louisiana, which was temporarily under the authority of Indiana Territory, and the organized Orleans Territory, which corresponded to part of present-day Louisiana with a small portion of Texas. The western border of Orleans Territory caused further conflict with New Spain, specifically over the region between the Sabine River on the west and the Arroyo Hondo (River) on the east, which became known as the Sabine Free State. This land was later confirmed as U.S. territory by the Adams-Onís Treaty of 1819.

[[Image:United States 1805-01-1805-07.png|250px|right]]

January 11 1805

Michigan Territory was split from Indiana Territory, including the whole of the lower peninsula of present-day Michigan but only that eastern tip of the upper peninsula which was held by the Northwest Territory after Indiana Territory had been split from it.

[[Image:United States 1805-07-1809.png|250px|right]]

July 4 1805

The District of Louisiana was organized as Louisiana Territory.

[[Image:United States 1809-1810-04.png|250px|right]]

March 1 1809

Illinois Territory was split from Indiana Territory. Illinois Territory included present-day Illinois, northeastern Minnesota, and Wisconsin. Indiana Territory included the present-day borders of Indiana, with its western and eastern borders continuing northward; thus, it also included the central portion of the upper peninsula of Michigan, as well as Door Peninsula of present-day Wisconsin.

1810s

[[Image:United States 1810-04-1810-10.png|250px|right]]

April 1810

The Hawaiian islands are unified as the Kingdom of Hawaii.

[[Image:United States 1810-10-1812-04.png|250px|right]]

October 27 1810

By proclamation by President James Madison, the United States annexed the Baton Rouge and Mobile Districts of West Florida, declaring them part of the Louisiana Purchase. These had, 90 days earlier, declared independence as the Republic of West Florida.

[[Image:United States 1812-04-1812-05.png|250px|right]]

April 30 1812

Orleans Territory was admitted as the 18th state, Louisiana.

[[Image:United States 1812-05-1812-06.png|250px|right]]

May 12 1812

The federal government annexed a part of West Florida, the Mobile District, to Mississippi Territory, making the territory correspond to present-day Alabama and Mississippi.

[[Image:United States 1812-06-1816.png|250px|right]]

June 4 1812

Louisiana Territory, having the same name as a state, was renamed to Missouri Territory.

[[Image:United States 1816-1817-03.png|250px|right]]

December 11 1816

The southern portion of Indiana Territory was admitted as the 19th state, Indiana. The remainder became unorganized.

[[Image:United States 1817-03-1817-12.png|250px|right]]

March 3 1817

Alabama Territory was split from Mississippi Territory; both correspond to their present-day counterparts.

[[Image:United States 1817-12-1818-10.png|250px|right]]

December 10 1817

Mississippi Territory was admitted as the 20th state, Mississippi.

[[Image:United States 1818-10-1818-12.png|250px|right]]

October 20 1818

The Treaty of 1818 established the 49th parallel north west of the Lake of the Woods as the border with British-held lands, and Oregon Country was established as a shared land between the United States and United Kingdom. Oregon Country consisted of most of present-day Idaho and Oregon, all of Washington, and a portion of Montana, as well as the southern part of the Canadian province of British Columbia. The treaty transferred the Red River Basin to the United States, consisting of northwestern Minnesota, northeastern North Dakota, and the northeastern tip of South Dakota.

[[Image:United States 1818-12-1819-03.png|250px|right]]

December 3 1818

The southern portion of Illinois Territory was admitted as the 21st state, Illinois. The remainder was reassigned to Michigan Territory.

[[Image:United States 1819-03-1819-12.png|250px|right]]

March 2 1819

The southern part of Missouri Territory was organized as Arkansaw Territory, consisting of present-day Arkansas as well as part of Oklahoma. It was not officially spelled Arkansas until later.

[[Image:United States 1819-12-1820.png|250px|right]]

December 14 1819

Alabama Territory was admitted as the 22nd state, Alabama.

1820s

[[Image:United States 1820-1821-07.png|250px|right]]

March 16 1820

The Maine District of Massachusetts was split off and admitted as the 23rd state, Maine, as part of the Missouri Compromise.

[[Image:United States 1821-07-1821-08.png|250px|right]]

July 10 1821

The Adams-Onís Treaty came in to effect. It established the entirety of the border between the United States and New Spain. Under the terms of the treaty, all of Spanish Florida was sold to the United States. The treaty transferred the rest of present-day Idaho and Oregon to Oregon Country; moved portions of present-day Colorado, Oklahoma, and Wyoming, and all of New Mexico and Texas, to New Spain; and all of Florida to the United States. The new borders intruded on Arkansaw Territory's Miller County, created on April 1 1820, which dipped below the Red River and into land now ceded to Spain. However, the remoteness of the region caused no serious conflict with Spain.

[[Image:United States 1821-08-1822.png|250px|right]]

August 10 1821

The southeastern corner of Missouri Territory was admitted as the 24th state, Missouri. The remainder became unorganized. Missouri did not include its northwestern triangle at this point, that being added later in the Platte Purchase.

September 27 1821

The Viceroyality of New Spain achieved independence as Mexico.

[[Image:United States 1822-1824.png|250px|right]]

March 30 1822

East Florida and the portion of West Florida not already part of other states were combined and organized as Florida Territory, which corresponded to present-day Florida. Around this time, the official spelling of Arkansaw Territory became Arkansas Territory.

[[Image:United States 1824-1828.png|250px|right]]

November 15 1824

Arkansas Territory was shrunk, the western portion becoming unorganized.

[[Image:United States 1828-1834.png|250px|right]]

May 6 1828

Arkansas Territory was shrunk further, attaining the present-day borders of Arkansas, with the remainder again becoming unorganized, excepting the land it still claimed as Miller County.

1830s

[[Image:United States 1834-1836-03.png|250px|right]]

June 30 1834

A large portion of unorganized land was added to Michigan Territory, corresponding to present-day Iowa, western Minnesota, and eastern North Dakota and South Dakota.

[[Image:United States 1836-03-1836-06.png|250px|right]]

March 2 1836

The Republic of Texas achieved independence from Mexico, though with a large portion of the territory disputed. It had control over the eastern half of present-day Texas, and disputed the western half, as well as portions of Colorado, Kansas, New Mexico, and Wyoming. Miller County in Arkansas Territory now intruded on the borders of Texas, and the people there began to take a Texian identity, leading to both governments having representatives from the county.

[[Image:United States 1836-06-1836-07.png|250px|right]]

June 15 1836

Arkansas Territory was admitted as the 25th state, Arkansas. It continued to claim Miller County, with increasing irrelevance.

[[Image:United States 1836-07-1837-01.png|250px|right]]

July 4 1836

Wisconsin Territory was split off from Michigan Territory, consisting of present-day Wisconsin and the northeastern portion of Minnesota. As an inducement to give up its claim over the Toledo Strip to Ohio, the whole of the present-day upper peninsula was assigned to Michigan Territory, giving it the present-day borders of Michigan.

[[Image:United States 1837-01-1837-03.png|250px|right]]

January 26 1837

Michigan Territory was admitted as the 26th state, Michigan.

[[Image:United States 1837-03-1838.png|250px|right]]

March 28 1837

The Platte Purchase added a small area of land to Missouri, giving it its present-day boundaries.

[[Image:United States 1838-1842.png|250px|right]]

July 4 1838

Iowa Territory was split off from Wisconsin Territory, consisting of present-day Iowa, western Minnesota, and eastern North Dakota and South Dakota, leaving Wisconsin Territory with northeastern Minnesota and Wisconsin.

1840s

[[Image:United States 1842-1845-03.png|250px|right]]

November 10 1842

The Webster-Ashburton Treaty settled the border between the United States and lands held by the United Kingdom east of the Rocky Mountains, ending the dispute over the borders of Maine and northeastern Minnesota.

[[Image:United States 1845-03-1845-12.png|250px|right]]

March 3 1845

Florida Territory was admitted as the 27th state, Florida.

[[Image:United States 1845-12-1846-06.png|250px|right]]

December 29 1845

The Republic of Texas was admitted as the 28th state, Texas. It was annexed by the United States on March 1 1845, but Texas did not agree to join the union for some time after. It brought with it all the lands of Mexico that it claimed, including all of present-day Texas, and parts of Colorado, New Mexico, Oklahoma, and Wyoming. With Texas joining the union, Arkansas finally gave up its claim on Miller County.

[[Image:United States 1846-06-1846-12.png|250px|right]]

June 18 1846

The Oregon Treaty established the 49th parallel west of the Lake of the Woods as the continental border (so it did not include Vancouver Island) with the lands held by the United Kingdom. The sharing of Oregon Country ended, and the American portion becomes unorganized territory.

[[Image:United States 1846-12-1848-02.png|250px|right]]

December 28 1846

The southeast portion of Iowa Territory was admitted as the 29th state, Iowa. The remainder became unorganized.

March 13 1847

The District of Columbia retroceded its land south of the Potomac River back to Virginia. Congress passed the retrocession act on July 9 1846, and Virginia took possession of the land on this date.

[[Image:United States 1848-02-1848-05.png|250px|right]]

February 2 1848

The Treaty of Guadalupe Hidalgo, ending the Mexican-American War, granted a large area of land to the United States from Mexico. It consisted of all of present-day California, Nevada, and Utah, most of Arizona, and portions of Colorado, New Mexico, and Wyoming.

[[Image:United States 1848-05-1848-08.png|250px|right]]

May 29 1848

The southeastern portion of Wisconsin Territory was admitted as the 30th state, Wisconsin. The remainder became unorganized.

[[Image:United States 1848-08-1849.png|250px|right]]

August 14 1848

Oregon Territory was organized, including present-day Idaho, northwestern Montana, Oregon, Washington, and western Wyoming.

[[Image:United States 1849-1850.png|250px|right]]

March 3 1849

Minnesota Territory was organized, consisting of present-day Minnesota, and eastern portions of North Dakota and South Dakota.

1850s

[[Image:United States 1850-1853-03.png|250px|right]]

September 9 1850

The Mexican Cession was divided as part of the Compromise of 1850. The western portion was admitted as the 31st state, California. The rest was organized as Utah Territory and New Mexico Territory. Both territories also included land ceded to the federal government by Texas in exchange for taking on its debts; a portion of Texas and the Mexican Cession became unorganized land. A peculiarity appeared at this time, when a small strip of land north of Texas was not officially assigned by any state or territory; this came to be called the Neutral Strip or "No Man's Land", which corresponds to the present-day panhandle of Oklahoma. New Mexico Territory consisted of most of present-day Arizona and New Mexico, as well as a southern portion of Colorado and the southern tip of Nevada. Utah Territory consisted of present-day Utah, most of Nevada, and portions of Colorado and Wyoming.

[[Image:United States 1853-03-1853-12.png|250px|right]]

March 2 1853

Washington Territory was split from Oregon Territory, consisting of present-day Washington, northern Idaho, and the western tip of Montana, leaving Oregon Territory with all of Oregon, southern Idaho and a portion of Wyoming.

[[Image:United States 1853-12-1854.png|250px|right]]

December 30 1853

The Gadsden Purchase added some land to New Mexico Territory, corresponding to the southernmost areas of present-day Arizona and New Mexico.

[[Image:United States 1854-1858.png|250px|right]]

May 30 1854

Kansas Territory and Nebraska Territory were organized; the remaining unorganized land colloquially became known as Indian Territory. Kansas Territory consisted of present-day Kansas and eastern Colorado. Nebraska Territory consisted of present-day Nebraska, and parts of Colorado, Montana, North Dakota, South Dakota, and Wyoming. Indian Territory corresponds to eastern Oklahoma.

[[Image:United States 1858-1859.png|250px|right]]

May 11 1858

The eastern portion of Minnesota Territory was admitted as the 32nd state, Minnesota. The remainder became unorganized.

[[Image:United States 1859-1860.png|250px|right]]

February 14 1859

The western portion of Oregon Territory was admitted as the 33rd state, Oregon. The remainder was assigned to Washington Territory.

1860s

[[Image:United States 1860-1861-01.png|250px|right]]

February 8 1860

Texas began claiming Greer County, Texas, controlled at that time by the federal government as unorganized territory, and now in present-day Oklahoma.

[[Image:United States 1861-01-1861-02-04.png|250px|right]]

January 29 1861

The eastern portion of Kansas Territory was admitted as the 34th state, Kansas. A peculiarity arose for the western portion. It was added to Colorado Territory on February 28 1861; however, for the month between statehood for Kansas and the Colorado Territory being formed, it appears to have had no official status.

[[Image:United States 1861-02-04-1861-02-28.png|250px|right]]

February 4 1861

The Confederate States of America (CSA) was formed. The Southern states seceded at different dates and joined the CSA at different dates; to simplify the map, only the final form of the CSA is shown here. There were rebel governments as well as Union governments in Kentucky and Missouri, and the CSA had full control over Indian Territory. To view a detailed animated map depicting the various state secessions see CSA states evolution.

[[Image:United States 1861-02-28-1861-03.png|250px|right]]

February 28 1861

Colorado Territory was organized, with land from Utah, New Mexico, and Nebraska Territories, as well as the land left over from Kansas Territory; it corresponded already to present-day Colorado.

[[Image:United States 1861-03-1861-08.png|250px|right]]

March 2 1861

Dakota Territory was split from Nebraska Territory, and included the unorganized land left over from Minnesota Territory. Dakota Territory consisted of both present-day North and South Dakota, as well as most of Montana and northern Wyoming. Nebraska Territory consisted of all of Nebraska and southeastern Wyoming. Nevada Territory was split from Utah Territory, corresponding to northwestern present-day Nevada; the eastern border was the 39th meridian west of Washington, D.C.

[[Image:United States 1861-08-1862.png|250px|right]]

August 1 1861

The Confederacy established Arizona Territory (CSA) in the southern half of the Union's New Mexico Territory. It would be organized on February 14 1862. It corresponded to the southern halves of present-day Arizona and New Mexico.

[[Image:United States 1862-1863-02.png|250px|right]]

July 14 1862

Due to its nature as a mining and grazing area, land started to be added to Nevada Territory to accommodate these activities. Its eastern border was moved eastward from the 39th meridian west from Washington, to the 38th meridian west from Washington, transferring the land from Utah Territory.

[[Image:United States 1863-02-1863-03.png|250px|right]]

February 24 1863

The Union created its own Arizona Territory, splitting it off from New Mexico Territory, making both territories correspond to their present-day states, except for Arizona Territory including the southern tip of present-day Nevada.

[[Image:United States 1863-03-1863-06.png|250px|right]]

March 4 1863

Idaho Territory was created from portions of Washington, Dakota, and Nebraska Territories, consisting of present-day Idaho, Montana, and most of Wyoming. Nebraska and Washington Territories were left corresponding to their present-day counterparts.

[[Image:United States 1863-06-1864-05.png|250px|right]]

June 20 1863

Several counties of northwestern Virginia who didn't want to be part of the Confederacy split off and were admitted as the 35th state, West Virginia.

[[Image:United States 1864-05-1864-10.png|250px|right]]

May 26 1864

Montana Territory was split from Idaho Territory, which also had some land transferred to Dakota Territory. Montana Territory corresponded to present-day Montana, Idaho Territory consisted of Idaho and western Wyoming, and Dakota Territory included both North and South Dakota, and most of Wyoming.

[[Image:United States 1864-10-1865.png|250px|right]]

October 31 1864

Nevada Territory was admitted as the 36th state, Nevada; it was a bit smaller than it is today, lacking area in both the east and south.

[[Image:United States 1865-1866.png|250px|right]]

April 9 1865

The Confederate States of America surrendered. The process of Reconstruction and readmission to the union would take several years; to simplify the map, they are shown as already readmitted. To view a detailed animated map depicting the various state readmission during Reconstruction see CSA states evolution.

[[Image:United States 1866-1867-01.png|250px|right]]

May 5 1866

Nevada's eastern border was moved from the 38th meridian west from Washington, to the 37th meridian west from Washington, transferring land to it from Utah Territory.

[[Image:United States 1867-01-1867-03.png|250px|right]]

January 18 1867

The northwestern corner of Arizona Territory was transferred to the state of Nevada, giving it its present-day borders.

[[Image:United States 1867-03-1867-10.png|250px|right]]

March 1 1867

Nebraska Territory was admitted as the 37th state, Nebraska.

[[Image:United States 1867-10-1868.png|250px|right]]

October 11 1867

The United States purchased Alaska from Russia; it was designated the Department of Alaska, and corresponds, except for a boundary dispute, to present-day Alaska.

[[Image:United States 1868-1876.png|250px|right]]

July 25 1868

Wyoming Territory was formed from portions of Dakota, Idaho, and Utah Territories, corresponding to the present-day borders of Wyoming.

1870s

[[Image:United States 1876-1884.png|250px|right]]

August 1 1876

Colorado Territory was admitted as the 38th state, Colorado.

1880s

March 28 1882

The part of Dakota Territory south of 43° north and north of the Keya Paha and Niobrara Rivers was transferred to Nebraska.

[[Image:United States 1884-1889-11-02.png|250px|right]]

May 17 1884

The Department of Alaska, previously under the direct control of the federal government and the military, was redesignated the District of Alaska, forming a local government.

[[Image:United States 1889-11-02-1889-11-08.png|250px|right]]

November 2 1889

Dakota Territory was split in two, and it was admitted as the 39th state, North Dakota, and 40th state, South Dakota.

[[Image:United States 1889-11-08-1889-11-11.png|250px|right]]

November 8 1889

Montana Territory was admitted as the 41st state, Montana.

[[Image:United States 1889-11-11-1890-05.png|250px|right]]

November 11 1889

Washington Territory was admitted as the 42nd state, Washington.

1890s

[[Image:United States 1890-05-1890-07-03.png|250px|right]]

May 2 1890

Oklahoma Territory was organized from the western portion of Indian Territory, and included the Neutral Strip, and corresponded to the western half of present-day Oklahoma.

[[Image:United States 1890-07-03-1890-07-10.png|250px|right]]

July 3 1890

Idaho Territory was admitted as the 43rd state, Idaho.

[[Image:United States 1890-07-10-1896-01.png|250px|right]]

July 10 1890

Wyoming Territory was admitted as the 44th state, Wyoming.

July 4 1894

The Kingdom of Hawaii became the Republic of Hawaii.

[[Image:United States 1896-01-1896-05.png|250px|right]]

January 4 1896

Utah Territory was admitted as the 45th state, Utah.

[[Image:United States 1896-05-1898.png|250px|right]]

May 4 1896

A Supreme Court ruling officially assigns Greer County to Oklahoma Territory.

[[Image:United States 1898-1907.png|250px|right]]

August 12 1898

The Republic of Hawaii was annexed by the United States.

20th century

June 14 1900

The annexed Hawaiian islands were organized as the Territory of Hawaii, and corresponded, except for including Palmyra Atoll, to the present-day state of Hawaii.

October 20 1903

The Alaska boundary dispute is resolved by arbitration, generally favoring the American claim.

[[Image:United States 1907-1912-01.png|250px|right]]

November 16 1907

Oklahoma Territory and Indian Territory were combined and admitted as the 46th state, Oklahoma.

[[Image:United States 1912-01-1912-02.png|250px|right]]

January 6 1912

New Mexico Territory was admitted as the 47th state, New Mexico.

[[Image:United States 1912-02-1912-08.png|250px|right]]

February 14 1912

Arizona Territory was admitted as the 48th state, Arizona.

[[Image:United States 1912-08-1959-01.png|250px|right]]

August 24 1912

The District of Alaska was organized as Alaska Territory.

[[Image:Delaware-wedge.svg|250px|right]] ;[[March 28]] [[1921]] The dispute over a square mile between [[Delaware]] and [[Pennsylvania]], [[The Wedge (border)|The Wedge]], is finally resolved in favor of Delaware.<ref>{{cite web|url=http://ucblibraries.colorado.edu/govpubs/conference/handouts/Erie/Erie.ppt |title=The Erie Triangle |format=PPT |accessdate=2007-08-01}}</ref> {{-}} <nowiki>[[Image:United States 1959-01-1959-08.png|250px|right]]

January 3 1959

Alaska Territory was admitted as the 49th state, Alaska

[[Image:United States 1959-08-present.png|250px|right]]

August 21 1959

Hawaii Territory was admitted as the 50th state, Hawaii, resulting in the present-day situation of the United States. The statehood act specifically excluded Palmyra Atoll from the new state; it thus became unorganized land. Since it had been incorporated as part of the Hawaii Territory, Palmyra Atoll became the only incorporated territory left in the United States.

See also

• Geography of the United States
• History of the United States
• List of U.S. states by date of statehood
• United States territorial acquisitions
• United States territory
• U.S. state