The Chickasaw Nation is a Native American nation that was part one of the Five Civilized Tribes in the United States. The Five Civlized Tribes were differentiated from other Indian reservations in that they had semi-autonomous constitutional governments and delegates in the U.S. House of Representatives. The Chickasaw Nation was created after the Chickasaws were removed to Indian Territory in the 1830s.
The Chickasaws were first combined with the Choctaw Nation and their area in the western area of the nation was called the Chickasaw District. It consisted of Panola, Wichita, Caddo, and Perry counties. Although originally the western boundary of the Choctaw Nation extended to the 100th Meridian, virtually no Chickasaws lived west of the Cross Timbers due to continual raiding by the Indians on the Southern Plains. The United States eventually leased the area between the 100th and 98th meridians for the use of the Plains tribes. The area was referred to as the "Leased District".
The division of the Choctaw Nation was ratified by the Choctaw–Chickasaw Treaty of 1854. The Chickasaw constitution establishing the nation as separate from the Choctaws, was signed August 30, 1856, in the new capitol of Tishomingo (now Tishomingo, Oklahoma). The first governor was Cyrus Harris. The nation consisted of five divisions; Tishomingo County, Pontotoc County, Pickens County, and Ponola County. Law enforcement was by the Chickasaw Lighthorsemen, although non-Indians fell under the jusidictions of the Federal court at Fort Smith.
Following the Civil War—although the Five Civilized Tribes did not suffer the Reconstruction of other Confederacy supporters—for their abrogation of their treaties, the United States forced them into new treaties. Under the new treaty, the Chickasaws (and Choctaws) ceded the "Leased District" to the United States. In 1868, Chickasaw Montford T. Johnson, with Jesse Chisholm's help, secured an agreement with the Plains tribes to establish a ranch on the new western edge of the Nation. His ranch was never raided, although often threatened. He and his family remained the only permanent residents of the area until the settlement of Oklahoma.
The nation was dissolved before statehood by agreement negotionated with the Dawes Commission. Following the breakup of the nation the Chickasaws became citizens of the United States and their non-allotted lands opened for settlement by non-Indians.