BTW-isn't obammy half white? I mean...why is he considered black? Because he married a black?
European slave traders did not even enter the picture until the late 15th century and then it was only the Iberian Europeans.
The northern and northeast Africans were in about the 6th or 7th century of practicing slavery by then. In fact, it was the forced conversion to Islam which turned large swaths Africa from Egypt to Nigeria from being among the most advanced civilizations in the world at the time of Mohammad into being virtually destroyed by the time the Portuguese begin to explore it in depth by the early 15th century, to be followed by the Spanish, who looked at Africa as a source of cheap labor to develop their holdings in the Americas.
Indeed, the mortality rate was so poor among slaves sent to present day Latin America that the British, Dutch and slave traders which came into the sorry trade over the next two centuries were considered benevolent.
Indeed, one of the early justifications for slavery was the higher civilizations of northern Europe were saving lives by rescuing the people of west central Africa from the aggressive tribes of northeast Africa who would either (a)kill them, (b)work them to death or (c)sell them to the Iberians who would work them to death.