Though the Civil War was over 150 years ago, the social fabric of the United States still suffers from the country’s former divisions. Cultural and political values are split between the so-called free counties and the former slave counties, which existed in 15 states (only 11 of which seceded during the Civil War). Now, a new study has shown one of the most peculiar, yet perhaps unsurprising, divisions between former slaveholding and free parts of the U.S.: the prevalence of slavery in a given county correlates closely to the prevalence of firearms owned by its residents.

The researchers, led by psychology professor Dr. Nicholas Buttrick of the University of Wisconsin-Madison, hypothesize that this correlation exists because of the Reconstruction period in American […]