The cultural complex of the Mississippian Period is best described as the inhabitants of the area encompassing the Ohio and Mississippi River Valley East to the Appalachians and South to the Gulf Coast and East to Alabama, Georgia, Northern Florida, South Carolina, and Central and Western North Carolina, and Tennessee.
Other distinct marks of this era was the intensive corn-based agriculture and the construction of large flat or platform mounds. Monumental Ceremonial Centers such as present day Cahokia Mounds, in Southern Illinois, Moundville in Alabama, Etowah in Georgia, and Spiro in Oklahoma are dominated by platform mounds which were bases for religious buildings as well as a residence of leaders.
The Mississippian Period was brought to an end by the increasing European presence in the Southeast. European diseases introduced by early explorers and colonists devasted native populations in some areas, and the desire for European goods and the trade in native slaves, and later, deerskins caused whole social groups to relocate closer to or farther from European settlements. The result was the collapse of native chiefdoms as their populations were reduced, their authority structures were destroyed by European trade, and their people scattered across the region. Many remnant populations of these ancient Muscogean people came together to form historically known native groups - the Creeks, Chickasaws, Choctaws, and Seminoles, and remained in the southeast until the forced and brutal removal of the majority to Indian Territory in the 1830's.