Simply because there were blacks who owned slaves does not absolve white slave owners from their reprehensible behavior. Slave owners, no matter what their race or the time they lived committed a Crime Against Humanity.
If you read all I posted, you'll see that IN THE 1700'S, wrong as we now know it is, it WAS a customary practice around the world, that obviously gradually evolved into the abomination of slavery.
This is a magnificent country that evolved over 200+ years. As a society endures, folks hopefully become educated and civilized. Women were treated as chattel at one time here, too .. abusive child labor was common, as well. Those issues set you off, too ?