Why did slaves come from Africa?

Answer by  quisqualis (1756)

When there was a labor shortage in the New World, the explorers of the Old World discovered the slave-traders of the coast of Africa, where slavery was a small industry. It was a match made in hell, as plantation agriculture needed the slavers and vice-versa. Slavery was not unknown in other places, but the quantity and quality came from Africa.

Answer by  jude11 (499)

Well, pretty much the Europeans saw that there was not only gold in Africa, but leaders of the tribes who were willing to sell their people off for money. At the time, Japan and Iran weren't on their list of conquered places essentially.