system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is there such a high concentration of religious conservatives in the South in the US?
gpt
The northern states were mostly farm colonies, and the southern states were mostly exploitation colonies.  Those kind of places in the world tend to be poorer, slave colonies that tend to not have had a strong secular system set up, so you get a larger amount of church control over things due to lack of qualified leadership.  Lack of secular systems and education, lead to an overall decrease in the education and knowledge base of the people, which can be more conducive to religious/fundamentalist groups.

For example, part of New England, Argentina, and other places were farm colonies.  People went there to establish institutions and become farmers and permanently live there.  So although church is important, fundamental craziness was kept in check.

Places like Mississippi, El Salvador, etc, were exploitation colonies, where rich nobility invested in heavy labor cash crops, slavery, and wanted to get their money and go home.  They had no interest in permanent institutions so they could get their money and go home.  People are kept in line with religion and other methods, but people are kept poor and uneducated and even when the colonists leave, there's no permanent institutions to run a functioning secular government, and when you have poor, uneducated, people without a functional government, churches do well in these areas.

Fast forward a few hundred years, and you still see the ramifications of farm vs. exploitation colonies, and you'll see areas of more powerful religious fundamentalism vs. more secularized areas where people tried to make a new world for themselves.

Look around the Western Hemisphere and the history of places in South and North America where there was exploitation vs. farm communities, and you'll see pretty much a corresponding level of fundamentalist religion vs. more liberal church participation in the current era.