Slavery might have ended on paper after the Civil War, but many white landowners did everything they could to exploit newly freed slaves well into the 20th century. Thousands of black laborers across the South were forced to work against their will as late as the 1960s—a new form of enslavement that went on in the shadows of rural America.

As African heads of state sign the first continent wide free trade deal, what will it mean for the people that live there? The BBC’s Nancy Kacungira explains.