Research focusing on the political economy of Mississippian mound centers in the middle Savannah River valley has prompted a reevaluation of current interpretations regarding societal complexity. I conclude the clearest expression of classic Mississippian riverine-adaptation is evident at centers immediately below the Fall Line with their political ties to chiefdom centers in the Piedmont, and especially Etowah. By contrast, those centers on the interior Coastal Plain were politically autonomous with minimal signatures in social ranking. The scale of appropriated labor and resulting level of surplus production, necessitated by upland settlement on the Aiken Plateau, fostered social contradictions making communally-oriented and decentralized societies more sustainable than hierarchical forms.