Contrary to the diplomas MAGAts have earned from Google High School, the Civil War was fought over slavery. More specifically, it was fought over whether slavery would be allowed to expand. Lincoln was not even demanding the end of slavery, merely restrictions on its spread. Not many southerners owned slaves, and fewer still owned more than a few slaves Whether slavery expanded or not made little difference in their lives. They fought and died to preserve the wealth of their feudal oligarchs and for a system that modern economic analysis shows was hurting the average White southerner: if labor was free and slaves could fulfill needs for craftwork, there was little need to pay for White workers and little need for a middle class of entrepreneurs. Other than some farm owners, there was not much of a middle class in the South.
The average White southerner fought and died for a struggle that was contrary to their true self-interest. The question is why? There were a few reasons. They had been trained to obedience by generations of quasi-feudalism. Also, there is the regional chauvinism one always finds among the poorly educated especially - a kind of tribal instinct. I think the main reason, though, was that as long as there were oppressed Black people around, southern losers could tell themselves that as sad as they were, at least they weren't black. This seems to be the force that continues to drive cowardly southern bigots today. Of course, as the freed slave moved North, we saw the same effects and results on Northern losers, and see it still today.
Revisionist bigots like to point to other disputes that did indeed exist. For example, the South threatened several times to secede over tariffs that protected northern industries but made everything more expensive for southerners. When Calhoun threatened to secede over tariffs, Jackson said he would hang the first "nullifier" he could find from the first tree he could find. (Nullifiers believed states had the right to "nullify" federal laws). Southern threats of secession fizzled. Of course, everybody has heard poorly educated apologists for Southern treason squawk, "It was about STATES' RIGHTS!" It works on those who lack the critical thinking skills to ask, "What rights?" There was only one. America's Third World had bitched since our creation about one thing or another. There was only ONE reason they were willing to fight for, though: the demand that slavery be allowed everywhere.