Farming under Fire in the Central Illinois River Valley: Changes in Farming Strategies in Response to Intensified Warfare during the Mississippian Period

An examination of the effects of intensified warfare on subsistence strategies in the Mississippian-period Central Illinois River Valley (CIRV) demonstrates that safety concerns after AD 1200 were significant enough that villagers reduced foraging forays and narrowed diet breadth to focus on maize farming.  Despite this shift towards a focus on maize, standard abundance measures reveal that farmers did not increase yields.  We closely explore shifts in farming strategies through an examination of maize varieties.  Metric measurements indicate that maize kernel size decreases significantly after AD 1200 and that an additional variety was added to the cultivation repertoire around AD 1250, alongside the common bean.  We argue that size decreases in maize kernels resulted from earlier harvesting to offset food shortages.  We further suggest that villagers dealt with the increasing risk of food shortage by adding beans and a new variety of maize to their system of food production.