The other question about the Confederacy, of course, is what would have happened if they had managed to abolish slavery fairly early on. I suppose one could construct some sort of "blowback" argument whereby American intervention hardened racial attitudes and made white Southerners act nastier to blacks than they otherwise would have been . . . . but such an argument would be hilariously unconvincing.

It is hard to imagine a Confederacy with a Civil Rights Act. School segregation probably have been less of a problem; I doubt there would have been too many schools for black kids. Legal discrimination would be buttressed with the sort of social and economic discrimination that America (read, the North) legally prosecuted for decades. Confederate apartheid, unlike the the African version, commanded the support of actual majorities of the population in most places, so even if you gave blacks the vote, it's not clear to me how it would have ended.