This is an end result of a nation expanding its geographical territory far beyond the ability of the society to expand its education and cultural influence. “Give me your tired, your poor, your huddled masses too dumb to farm where they were."

Then we sent them into virtual exile without contact with civilization for multiple generations. When we finally got around to reuniting them with our world after the civil war and the ability to travel by rail and communicate by telegraph we found their ignorance and superstition had actually multiplied and morphed into something entirely alien.

The lines they represented are still quite visible when one looks at a map of political alignments. The coastal areas that had better communication with their cultural centers and access to higher education progressed and thrived. The low intellect of the center of the nation regressed into multiple new religions and a neanderthal like social organization structured around their heirarchy of brutality.