America was divided. One side had a vibrant, growing, state of the art economy; it was socially progressive, and embraced (albeit sometimes grudgingly) people of a variety of ethnicities. The other side depended to a large extent on commodities. It was growing much more slowly, and viewed the progressive ideas of the first side with suspicion. To a majority of its residents, the natural order of things was for white men to rule. It reacted violently to anyone who suggested otherwise.
Is it 1860 or 2020? You decide.