One hundred million years ago, the coastline of North America was drastically different than it is now. First off, the precursors of the Rocky Mountains, stretching from the tip of Alaska to Central America, were their own island, separated from the eastern states by the ocean. Florida was under water, as was much of Georgia, Alabama, Mississippi, and Louisiana. And this ancient coastline, which became the Deep South after the waters receded, could swing this year’s election.
During the Cretaceous, 139-65 million years ago, shallow seas covered much of the southern United States. These tropical waters were productive–giving rise to tiny marine plankton with carbonate skeletons which over time accumulated into massive chalk formations. The chalk, both alkaline and porous, lead to fertile and well-drained soils in a band, mirroring that ancient coastline and stretching across the now much drier South. This arc of rich and dark soils in Alabama has long been known as the Black Belt.
McClain notes that these particularly fertile soils contributed to the region’s cotton boom. High cotton productivity lead to a higher number of slaves being brought in to work in the fields, which, come the abolition of slavery, meant a narrow band cutting through the south with a predominantly black population.
This Black Belt with its predominantly African American population consistently votes overwhelmingly for Democratic candidates in presidential elections. The pattern is especially pronounced on maps when a Republican candidate has secured the presidency as Bush did in 2000 and 2004. In Southern states where a Republican secures the nomination, almost the entirety of Black Belt counties still lean Democratic.
It’s an interesting reminder that the fate of human civilizations isn’t completely removed from the world around them.
More from Smithsonian.com: