Lest anyone think this is an exaggeration of what ace said, it actually is the tamest thing he said in that thread. Start here and scroll down through his next half-dozen posts. If you make it down to where he admits that maybe life was bad for the 1st generation slaves but by the 2nd and 3rd generation they were used to it, then I apologize for pointing you toward that fetid cesspool.
As he says, maybe slavery was bad, but who really knows. “It was a highly complicated issue.”