Digby calls this an American problem, but actually I don’t think it is all that unique to us. At various points in time, parts of Europe and the Middle East have definitely been afflicted with this set of delusions, and I daresay other parts of the world as well.
Granting the existence of cultural differences between the North and South, can we assume that they would necessarily lead to a Civil War? Obviously not. Such differences lead to animosity and war only if one side develops a national inferiority complex, begins to blame all its shortcomings on the other side, enforces a rigid conformity on its own people, and tries to make up for its own sins of omission and commission by name-calling, by nursing an exaggerated pride and sensitiveness, and by cultivating a reckless aggressiveness as a substitute for reason.