Oklahoma (ˌoʊkləˈhoʊmə; Choctaw: Oklahumma, oklahómma; ᎣᎧᎳᎰᎹ, , ògàlàhǒːmã́) is a state in the South Central region of the United States, bordered by the state of Texas to the south and west, Kansas to the north, Missouri to the northeast, Arkansas to the east, New Mexico to the west, and Colorado to the northwest. Partially in the western extreme of the Upland South, it is the 20th-most extensive and the 28th-most populous of the 50 United States. Its residents are known as Oklahomans and its capital and largest city is Oklahoma City.
The state's name is derived from the Choctaw words okla, 'people' and humma, which translates as 'red'. Oklahoma is also known informally by its nickname, "The Sooner State", in reference to the Sooners, settlers who staked their claims in the Unassigned Lands before the Indian Appropriations Act of 1889 authorized the Land Rush of 1889.
The land now known as Oklahoma has been inhabited since at least the last ice age. The Southern Plains villagers and the Mississippian people inhabited the area between roughly 800 and 1500. The Southern Plains Panhandle culture developed in the Oklahoma Panhandle in western Oklahoma while the Caddoan Mississippian culture inhabited the eastern parts of the state and included the major settlement of Spiro Mounds. The area was also inhabited by the Wichita people, Tonkawa people, and Caddo people. Between 1300 and 1500, the Plains Apache migrated into the Southern Great Plains (now western Oklahoma). During the 1700s, the Comanche people, Kiowa people, Osage people, and Quapaw people migrated into the region.
The first European contact with the region was the Spanish explorer Francisco Vázquez de Coronado in 1541. However, the land was claimed by the Kingdom of France's Louisiana colony and included in the Louisiana Purchase to the United States in 1803. Oklahoma was part of District of Louisiana (1804-1805), Louisiana Territory (1805-1812), Missouri Territory (1812-1821), Arkansas Territory (1819-1828), before finally being designated Indian Territory.