 Treaties with the tribes restricted entry of non-Indians into tribal areas; Indian tribes were largely self-governing, were suzerain nations, with established tribal governments and well established cultures.The region never had a formal government until after the American Civil War.After the Civil War, the Southern Treaty Commission re-wrote treaties with tribes that sided with the Confederacy, reducing the territory of the Five Civilized Tribes and providing land to resettle Plains Indians and tribes of the Midwestern United States.