The interesting part of the Civil War was how much it was expected for decades up to it actually happening. Those who opposed the war believed that slavery would go away on its own. They often cited new technology as an example why they didn't need it anymore. Heck, even founding fathers pointed towards that.

The fact that it didn't go away, and that the rivalry between states continued became worse and worse. Remember the reason why they rewrote the constitution was because the states had too much power and often openly fought each other. The Federalist papers used that as a reason for the new constitution. The antifederalist papers said that any power of the country against the state would then become over the citizen and they would be subjects again. This is why the amendments were placed that gave rights for weapons, speech, ect. Both were very important in the creation of the country and it's ideals.

The fact that both arguments continued and festered shows that they weren't fully done. Heck, even today they don't appear to be done.

So the idea that slavery, or the arguments around it would just go away don't seem to be possible.