Five Civilized Tribes
Five Civilized Tribes, a term used both officially and unofficially to designate the Cherokee, Chickasaw, Choctaw, Creek, and Seminole tribes of American Indians that were moved from the Southern states to Indian Territory (new Oklahoma). Most were moved by 1850. Their lands were not reservations, but were granted to them to hold in permanent ownership under treaties made with the Cherokees, the Choctaws, and the Creeks. Later the Chickasaws obtained land from the Choctaws, and the Seminoles from the Creeks.
Before removal, some of these tribes had become familiar with the institutions of their white neighbors, and in Indian Territory each set up a constitutional government with legislative, judicial, and executive departments. The tribes sold claims to lands in the western part of the territory, which became Oklahoma Territory in 1890. The two territories were reunited to become the state of Oklahoma in 1907.