Between 1000 and 700 years ago, the first people to practice large-scale agriculture in southern Illinois established Kincaid Mounds as the seat of their Chiefdom. These Native Americans were of the Mississippian culture and occupied Kincaid from approximately 1050 to 1450 AD. They were ruled by a chief who inherited his position and probably claimed power from the sun. Corn or maize farmers in the bottomlands along the Ohio River supplied the leaders with grain and constructed the mounds seen today. They also constructed the protective wall or palisade that encircled the principal mounds, now known only from the archaeological record. The mounds are raised platforms on which the Chief and other leaders of this society lived or ruled, and on which thatch-roofed ceremonial buildings, temples, and homes were constructed. The mounds were built in stages over a 400-year period by stacking basket loads of selected soil one on top of another. Flat-topped 30-foot-tall mounds arc around the level plaza area, which was probably the most important public place in the Chiefdom. It was used for both social and political activities. Here the important chunkey game was played and major ceremonies were held, including purification rituals and celebration of the new corn crop.