The US was suppose to be a framework representative 50 independent states for trade and defense, not a single top down authoritarian state. Slavery was invariably going to disappear independent of a civil war (was not the reason for it either, Lincoln didn't free all slaves, he used freeing southern slaves as a move to defeat the southern rebellion) and the resistance of the north has only hurt our long term well being. Many independent states is what we ought to have, not two nations.