Even on this very forum we have people that argue the slaves were better off as slaves in America than as free people in Africa.
Well, sure they are! And how can you tell that for certain? They refuse to go back. Ask! I often have, on forums: if you hate America so much and resent our bringing your ancestors here,
why don't you go back to Africa and live there?? They never do, though. I have even pointed out that a WHOLE lot of Americans would be willing to contribute to a fund to transport and start them off in Africa --- can you imagine? DNA cataloged so they couldn't return, nor could any offspring. This is an old idea, and Lincoln himself wanted to do it, but was assassinated too soon.
Of course the Founding Fathers thought slavery was a good thing, duh. For them, anyway. People don't do things unless they think they'll profit from it in some way.