Drought, Diet, Demography, and Diaspora during the Mississippian Period: A View from the Central Illinois River Valley

For decades archaeologists have conjectured about the impacts of climate change on the distribution of Mississippian and related pre-Columbian populations in midcontinental North America. Until recently, climatological reconstructions were coarse grained and lacked the temporal and spatial resolution to link in any substantive way with archaeological datasets on settlement size and distribution, subsistence, population movement, and biological relatedness. By that same token, archaeologists working in this region are only beginning to assemble operative databases to assess the relationship between the distribution of people and climate change. In this paper we examine the emergence, trajectory, and eventual decline of Mississippian polities in the central Illinois River valley (CIRV) of west-central Illinois. As a proximate hinterland to Cahokia and the American Bottom, the CIRV witnessed the development of early 11th century Mississippian centers, late 12th and 13th century consolidation into fortified towns and villages, and regional abandonment as part of the Vacant Quarter by the early 15th century. We investigate the variance in paleoethnobotanical, bioarchaeological, and settlement datasets from a series of time-transgressive Mississippian sites in the CIRV, comparing them to our recently developed high-resolution, multi-proxy lake sediment records that track midcontinental hydroclimate patterns over the last 2,000 years.