Honest Abe felt that the war, among other things, might end slavery, but again, that was not the reason that war was waged. It was felt that no major power would allow its southern half to simply walk off and become a separate nation. Southern secession put a serious crimp in plans for U.S. expansion (going back to A. Hamilton, among others), and had to stopped, which it was. Freeing the slaves was not one of the Rail Splitter's main concerns until the war was well underway.
>I think Marx had a thing or two to say on this subject.
Yes -- the bearded one supported Northern aggression. :)
Dennis