And if people don't think that slavery impacts some people today, my mother was telling me about some of my great aunts, children of slaves in the West Indies. People pass down stories and experiences. It's too bad that a lot of black Americans' ancestors needed Abe Lincoln's "unconstitutional" action to give them what they should have had in the US in the first place.
The institution of slavery was accompanied by all the other sorts of dehumanizing attitudes we anticipate finding anywhere totalitarianism gains a foothold.