Gettysburg was the turning point. The south was destroying the north in almost every battle, and pushing them back until they met in Gettysburg. The northerners dug in on a hill, and essentially camped their spots while the southerners got obliterated trying to move up the hill.

This sealed the deal essentially, and was a miscalculation by the general because he wanted to keep pushing hard. The south kicked the shit out of the north though overall considering they had less equipment, and industry. Also lincoln was a tyrant, and threw anyone in jail who disagreed with him. He should have let the confederacy be on their own, but he was greedy, and needed their warm water ports along with revenues.

Slavery had nothing to do with the civil war, and it was all brain washing in school to make you think that.