> Not that long ago, the majority view was that slavery was a great thing

A bit of a tangent, but is that actually the case? The highest estimate I have seen puts slave ownership at 5% of the population while the lowest puts it at 1%.

Obviously just because somebody doesn't own slaves doesn't mean they didn't support the system. There could be economic or legal reasons they couldn't own a slave.

I am just not sure that it was actually a majority view at any point in time in the US.