As ugly as it is by today's standards, slavery was the social norm during those times in the south.
Just as the social norm in the north was to cram immigrants into squalid tenements, make the father work 7 days a week, the mother take in sewing and washing, and have the children work as do piece work at home instead of going to school.
As miserable as those standards were, to say all factory owners and all slave owners were uniformly evil people is as ignorant as views were of blacks and immigrants often were at the time. Some were obviously way more enlightened than others.
For their times. Not ours.
But you guys excel at ignorance, so don't let me take you off your strides.
If you admit those "norms" were not so great, why are you trying so hard to return to them?