Answer:
The Territory of Oklahoma was an organized incorporated territory of the United States that existed from May 2, 1890, until November 16, 1907, when it was joined with the Indian Territory under a new constitution and admitted to the Union as the state of Oklahoma.
The 1890 Oklahoma Organic Act organized the western half of Indian Territory and a strip of country known as No Man's Land into Oklahoma Territory. Reservations in the new territory were then opened to settlement in a series of land runs in 1890, 1891, and 1893.
Seven counties were defined upon the creation of the territory. They were originally designated by number and eventually became Logan, Cleveland, Oklahoma, Canadian, Kingfisher, Payne, and Beaver counties. The Land Run of 1893 led to the addition of Kay, Grant, Woods, Garfield, Noble, and Pawnee counties. The territory acquired an additional county through the resolution of a boundary dispute with Texas, which today is split into Greer, Jackson, Harmon, and part of Beckham counties.
Red River Indian War, (1874–75), uprising of warriors from several Indian tribes thought to be peacefully settled on Oklahoma and Texas reservations, ending in the crushing of the Indian dissidents by the United States. Presumably the Treaty of Medicine Lodge (Kansas, October 1867) had placed on area reservations a number of Southwestern tribes: the Arapaho, Cheyenne, Comanche, Kiowa, and Kataka.
