Black people still own slaves. So do white, Asian and Arabs. Slavery didn't begin nor did it end with one isolated period in time and place, although Lord knows that's what alot of idiots in this country have been brainwashed into believing.
Furthermore, if we all could trace far enough back, we'd find both slaves and slave owners in our own family histories. As long as there's been war, there's been slavery. Hello, Roman Empire! Ancient Greece! Babylonian captivity of the Jews! Well, intelligent people already know this and people whose lavish livelihoods depend upon upholding the evil white slavemaster meme know it too, but their brainwashed followers don't and never will.
Here's a very interesting article about the Christian Balkan boys forcibly enslaved and converted to Islam (let's hope to hell the Left doesn't ever weaken us enough to repeat history)
http://www.jrnyquist.com/may14/balkan_boys.htm