I'm sorry, Dark, but you evidently have never read anything the Bible says about the 'sin' of slavery.
Please read Colossians, ch 13-14 if memory serves. Slavery is NOT a sin. In fact,the Bible gives very detailed instructions under which slavery is allowed to exist. In fact, the instructions on slavery are very similar to those on divorce- another practice that is allowed, under certain circumstances, although it has negative effects.
A study of the Slave Narratives, in their own words, shows the prodominant practices in the South followed the Apostle Paul's instructions.
Oy vey, this is gettin' scary. No offense, but I'm outta here. Have a good one.