The term civil war is something of an oxymoron, made to seem all the more so by the multiple meanings of the word 'civil'. No war is fought with civility, after all, and a civil war perhaps less so than some others. A civil war is one fought by and among a nation's own citizens. It is within the family, so to speak, and everyone is angry that other members of the family should have resorted to violence against themselves.
A colleague recently commented that the issues of the American Civil War could never really be resolved, and certainly not by force of arms. There will always, he suggested, be disagreement about where to draw the line between central (national) and distributed (state) authority. Thus he betrayed his southern roots.
My colleague is right enough about the philosophies of centralized authority, but he is wrong about the American Civil War. From the North's perspective, questions about state's rights were suppressed temporarily in order to deal with the more critical issues of Union and slavery. There were strong opinions in the North about the appropriate distribution of authority between state and federal governments, but Federal Rights was never a rallying cry to raise troops and moral support for the war. On the other hand, the abolition of slavery (even though it was not an official cause of war) was a rallying cry throughout the northern states. So was preservation of the Union, and that was the official cause of war from the Federal perspective. It was the permanence of the federal union which justified military action by Lincoln; the questions of States' Rights and of Abolition could, in this view, be fought out politically without recourse to arms.
The military historian John Keegan (in The Mask of Command) described the two sides as "the first truly ideological armies of history". The odd thing is that they weren't fighting from opposite positions concerning the same ideology; they were supporting differing interpretations of differing ideologies.
The citizens did not agree with each other on several ideological issues of importance, including slavery, balance between levels of government, and the nature of the union of states -- and of course economics -- and everyone knew this. The two sides also disagreed about which disagreements had led to the escalation of argument into battle.
After 150 years, and the passing of multiple generations, we still do not discuss the Civil War in common terms. It is a problem common to every family and every workplace that in many cases we argue vociferously our position on a question that our opponent is, at least at the moment, not contesting.