approximately thirteen million Africans were shipped north as slaves, often up the Arabian Gulf, to Arab and North African states. Second, one of the distinctives of American slavery (as opposed to, say, ancient Roman slavery) was that it was tied to blackness, to Africans. In the Roman Empire, there were African slaves, of course—but there were also Jewish slaves, Syrian slaves, Cilician Slaves, English slaves, Italian slaves. People sometimes became slaves out of bankruptcy, so there was no bar