Ok D3D, this problem is probably due to your poor understanding of English. History is not biased. A single source may be, but history as a whole is not.
-Also its irrelevant unless linked to the topic! I can't stress this enough.
Secondly, I have repeat myself again.
This isn't about muslims having slaves back in the day, this is about Islam itself. What Muhammed did and what God said was ok, has nothing to do with societal influences of the time.(at least in this context).