The union and the federal government fought to preserve the union, period. And only about 5% of Southern people owned slaves and in fact only slightly more than that had ever laid eyes on a slave. But the other 90% were sure pizzed about something. Pizzed enough to walk to a war and leave their starving families at home. It's fair to say and highly likely that the 5% feared losing their vast fortunes at some point before they died if the slaves were freed. But the other hard headed Scots, Irish and Celts fought for the same reasoning at the root of all wars. Tribal feelings. In the days before our entry into WW11 Americans were worried sick over what was going on in Europe. They knew it was only a matter of time before we got into it. The English were sons of bitches but they were "our sons of bitches"...tribal feelings.