I've not read it. Certainly the colonies were made of different sub-cultures, and that would and did have a major impact in self-identity in the colonies. But even in the South there were large differences from one State to the next, and that leaves slavery- and climate-caused industrialization disparities between North and South as the main drivers of that resentment of the North, and that chip on their shoulder almost certainly exacerbated the South's cultural attachment to slavery. By 1861 the people of the South definitely saw themselves as quite apart from the people of the North, and even quite apart from each other (organizing as a confederacy was not just to be starkly different from the federal North, but also because they had and wanted to maintain very strong national identities in each Southern State).