The war was about a lot of things. Slavery was one of those things. It wasn't the biggest or the smallest thing on the table, regardless of what certain people wuld like to tell us.
The central issue to the war was actually whether or not a state could leave the union. If the CSA states had not chosen to "take their ball and go home" there wouldn't have been a war. There may have been some heavyhanded enforcement in a place or two to force compliance but it would have been done at both a state and federal level with authorities cooperating with one another.
The CSA states saw a real issue of an increasing divide in the interests of their own states and those who remained in the USA. Their chosen means of dealing with this division was to make it formal and permanent by creating a new country that would have their interests at heart. It was a brave, risky, and foolish attempt that would have likley succeeded on a long term basis if the USA had not chosen to resort to arms. If the USA had simply packed up their soldiers from all CSA territories and marched home, we'd likely live in a very different and worse world today. The CSA would be your white trash buffer between you Yankees and Mexico. It would certainly be a poor nation.
The people who made the decisions in this war were neither noble nor altruistic. Their goals were all their own. Despite what anyone would have you believe, nobody crawled up on a cross and died for our sins between 1861 and 1865. A lot of men died for our stupidity, though. In the end, a nation was reforged, though.
Probably one of the biggest underlying resentments in the South to this day has nothing to do with the Reconstruction period. It has to do with the start of the war. 3/4 of the yahoos who ride around with rebel flags and have 50k worth of confederate money stashed at home in a chest would shut the hell up if the US history books listed the CSA as a nation instead of a bunch of rebel states. Everyone loses a fight sooner or later, we're just pissed that we don't get the basic respect of being called a country, short-lived though it was. The USA became a country the moment they shipped off a piece of paper that said "We quit" to England. Nobody wants to bring back slavery or fight another war. Just a little respect, that's all. Say we were a country when we declared independance and that we got invaded and absorbed against our will. It's the truth, after all. Is that too much to ask?