Often paired with the Fox tribe in negotiations with the U.S. government, the Sac were an Algonquin tribe located in the western Midwest, especially the Saginaw Valley. During the 18th Century, white settlers drove them out of Michigan and the tribe move to what became Illinois. The Sac primarily settled near Rock Island but a new treaty forced their removal to the Iowa Territory in 1832, resulting in the Black Hawk War. The revolt failed and the tribe remained in the territory until Iowa achieved statehood and a new treaty resettled them in the Kansas Territory.
William T. Hagan, The Sac and Fox Indians (Norman: University of Oklahoma Press, 1958), 3-15, 141-224; Patrick J. Jung, The Black Hawk War of 1832 (Norman: University of Oklahoma Press, 2007), 33-197.