I think we disagree on the social contract. I'd suggest the south had every right to dissolve their participation in the union - about the same as the Balkans and the Soviet Union. Furthermore, the odious taxes imposed by the union on the south were illegal, thus the north dissolved the union. A better question would be how the hell Lincoln came to the conclusion suspending the first amendment was a good thing. What is more defining of American liberty than the first amendment and federalism.
Additionally, most historians give lee credit for his surrender rather than going guerrilla. If you want to talk about war crimes, uh, Sherman? Little news flash, the civil was wasn't aboutslavery, that was the cover story you know like videos cause insurrection in lybia. Slavery could have been eliminated withouta war. There were advances by the south to do just that. The winner writes history