I think most political decisions are anything but altruistic, despite the terms they may be couched in. My view is that Lincoln fought for much the same reasons King George tried to stop the colonies from breaking away. The wealth and power of the surviving union would have been greatly diminished had the agriculturally productive southern states been allowed to secede. It might have even resulted in eventual loss of western territories that came under southern influence. Also, how would northern industry have fared after losing the southern market to “friendlier” European suppliers? There were plenty of hard nosed reasons to commit to war, but claims that cause of human liberty was the motivating factor don’t really ring true to me. It is a good way to stir people up to fight though. Do a little digging on the Corwin Amendment if you’ve never heard of it before. It’s not the kind of thing that makes it into the PC hagiographies we’ve been fed on Lincoln for decades.
Live in any fantasy world you choose. The Civil war was fought to end slavery.
If the Southern Patricians had said, your right, slavery is wrong, we henceforth free all our slaves. You think there’d still been a war?