In the border states, slavery was already dying out in urban areas and the regions without cotton. Several cities were rapidly industrializing, including Baltimore, Louisville, and St. Louis. By 1860, most of the African Americans in Delaware were free. By the start of the Civil War, slave ownership in the south had become concentrated into fewer and fewer hands. In 1830, 36% of Southern families owned slaves. By 1860, the number had fallen to 25%. In the Upper South it had fallen even more. In 1830, slaves made up 18% of the population. In 1860, they made up only 10%. During the same period in Kentucky, it fell from 24% to 19%. In Maryland, it went from 23% to 13%. Some slaveholders made a profit by selling surplus slaves to traders to be resold in the slave markets in the Deep South. They needed field hands for the cotton plantations.