Entitled: "The Georgia Negro: A social study by W.E.B Du Bois". Diagram shows routes of the African slave trade with state of Georgia starred. The chart was prepared by Du Bois for the Negro Exhibit of the American Section at the Paris Exposition Universelle in 1900 to show the economic and social progress of African-Americans since emancipation. Slavery in the United States was the legal institution of chattel slavery that existed in the USA in the 18th and 19th centuries. The US was polarized by slavery into slave and free states along the Mason-Dixon Line, which separated Maryland (slave) and Pennsylvania (free). Although the international slave trade was prohibited from 1808, internal slave-trading continued at a rapid pace, causing the forced migration of more than one million slaves from the Upper South to the Deep South in the antebellum years. The total slave population in the South eventually reached four million before abolition.