ok, I take back “minor”, that was inappropriate, but it is only “major” as proportion of US population (20+ mln), not in absolute scale. Just the Napoleonic wars had 3M soldiers and 1-3M civilians killed…
As you are saying, the N/S conflict existed for a long time and was somehow managed most of it. But that is only N/S. There are no other divisions? Just ponder why NY and NJ did not fight as France and Germany …