 The Sioux people consist of three main groups , the Lakota in the west , the Western Dakota in the center , and the Eastern Dakota in the east . In the east , the Santee was originally from the Minnesota area . The Chippewa or Ojibwe people were also from the same general area . The two tribes had been at war from at least 1736 and by 1750 the Chippewa had forced the Santee to the west into the prairie . The war between the tribes continued until at least the 1850s . Only after 1862 , when the Santee rose up against the whites and were subsequently removed to the Dakota Territory , did the fighting cease . In 1872 , the Sisseton and Wahpeton bands of the Santee signed a treaty that resulted in their moving to the Spirit Lake Reservation . 
