What was a major native American civilization in north America before 1400?

One of the most extensive and influential of all the early North American civilizations was Mississippi. Its cultural center was located on the floodplains of the lower Mississippi River and its tributary rivers.

Its people were descended from the hunter gatherers who had lived there for thousands of years. But unlike their predecessors, they lived in permanent villages. Around AD 900 many farming communities began to expand and the first large ceremonial centres and temple mounds were built. Cahokia, across the river from present day St Louis, Missouri was the largest of more than 40 ceremonial centers. Around AD 1100 the Mississippian culture extended from the Gulf of Mexico to the Great Lakes and from Oklahoma to the eastern slopes of the Appalachians.