The Atlantic slave trade prospered, with more than 470,000 slaves having been forcibly transported from Africa between 1626 and 1860 to what is now the United States. Prior to the Civil War, eight serving presidents owned slaves, a practice which was protected by the U.S. Constitution. Providing wealth for the white elite, approximately one in four Southern families held slaves prior to the Civil War. According to the 1860 U.S. census, there were about 385,000 slave owners out of a white population of approximately 7 million in the slave states.