Page "Indian Territory" Paragraph 86

At the beginning of the Civil War, Indian Territory had been essentially reduced to the boundaries of the future State of Oklahoma, and the primary residents of the Territory were members of the Five Civilized Tribes plus a number of Plains tribes that had been relocated to the western part of Indian Territory on land leased from the Five Civilized Tribes.

In 1861 the US abandoned Fort Washita, leaving the Chickasaw and Choctaw Nations defenseless against the Plains tribes.

Later the same year the Confederate States of America signed a Treaty with Choctaws and Chickasaws.

Ultimately, all of the Five Civilized Tribes, as well as several other tribes that had been relocated to the area, signed treaties of friendship with the Confederacy.