Most Missouri farmers practiced subsistence farming before the American Civil War. The majority of those who held slaves had fewer than five each. Planters, defined by some historians as those holding twenty slaves or more, were concentrated in the counties known as "Little Dixie," in the central part of the state along the Missouri River. The tensions over slavery chiefly had to do with the future of the state and nation. In 1860, enslaved African Americans made up less than 10% of the state's population of 1,182,012. In order to control the flooding of farmland and low-lying villages along the Mississippi, the state had completed construction of of levees along the river by 1860.