And who better to take down a bunch of racist scumbag plantation owners than a bunch of racist scumbag generals?
See, there were people, lots of them, who didn't agree with the secession, or slavery, but had to continue living there, because people in SC circa 1862 probably just couldn't pack their shit and get the fuck out of dodge. Lots of those people were killed in the course of the war, or had their homes destroyed, just for living there. Should have just wiped them all out, though. Not taken any chances. Like nowadays in the middle east, you know? Better to just wipe it off the earth. So there won't be any more terrorists, or oppression of women and minorities. Gotta break a few eggs, right?