The information on this page I got from a brochure from the Chieftains Trail from Calhoun, Georgia.
The last pre-historic cultural development in North American was the Mississippian Culture, thriving from apporcimately 800 A.D. until the arrival of European explorers. The Mississippian Culture spanned from Wisconsin and Minnesota in the north, through Georgia to the south, and westward into the Great Plains. These people enjoyed an intricate system of trading, were accomplished craftsman, and practiced sophisticated religious beliefs.
Chief Priests governed their fortified towns. These leaders lived in temples atop large earthern mounds overlooking a central ceremonial plaza. Lesser leaders might also live on mounds, but the tallest mound would be for the temple of the Chief Priest. Upon the death of the Chief Priest, his temple would would be destroyed and another layer of earth would be added for his successor. One's social standing would be reflected in how close his ho me was to the plaza.
Population centers were found in river basins, as their culture was sustained by the cultivation of crops. Towns were subordinated to other towns with more powerful Chief Priests; thus confederacies were established.
Although the Mississippian people, particularly the Chief Priests, were of significantly larger physical stature than the European explorers who encountered them, they had no immunities to the explorers diseases. Even the common cold was a killer. The spread of diseases introduced by the Europeans, as well as violent encounters, hastened the decline of the Mississippian Culture. The Creek Nation is believed to be the southeastern descendant of the Mississippian Culture.