Since we are discussing the RAT Rebellion “North” and “South” are not unwarranted distinctions. And it was the dumbasses in the Cornfederacy which tried to separate the regions.
Do you prefer “Traitors” and “Patriots”? “Dastardly Dimwitted Democrats” and “Loyal Americans”? Perhaps “Anti-Americans” and “Faithful Americans”?
There are any number of appropriate titles.