Prior to European colonization, the east bank of the Alabama River was inhabited by the Alibamu tribe of Native Americans. The Alibamu and the Coushatta, who lived on the west side of the river, were descended from the Mississippian culture. This civilization had numerous chiefdoms throughout the Midwest and South along the Mississippi and its tributaries, and had built massive earthwork mounds as part of their society about 950–1250 AD. Its largest location was at Cahokia, in present-day Illinois east of St. Louis.