The dumbest thing is that slavery is not racist. Racism came later.
If you haven't read or listened to the once openly Marxist Thomas Sowell he has some very powerful books that dispel all the lies about slavery, it's history and race (did you know the word slave comes from the word Slav as in Slavic people? And the Slavic people are so called white) This one below is real logn but just listen to the first 10 minutes and you will learn an awful lot about how misreported slavery is today.