文明化五部族
At the beginning of the Civil War, the Union Army was withdrawn from Indian Territory exposing the Five Civilized Tribes to aggression from the Plains Indians. The Confederacy filled the vacuum. All of the Five Civilized Tribes as well as other surrounding tribes signed treaties with the Confederacy. As a part of reconstruction, the Southern Treaty Commission was created by Congress to write new treaties with the Tribes that sided with the Confederacy.