Geology and political affiliation

Posted on November 9th, 2012 by

County results from the 2012 US Presidential election.

An interesting blog post titled “How presidential elections are impacted by a 100 million year old coastline” is making waves. The Black Belt region of Mississippi, Alabama, and Georgia corresponds to a band of Cretaceous chalk deposited by a shallow sea over 65 million years ago. This chalk is the parent material for the region’s rich soils–and, hence, name Black Belt–derive from. During its height, cotton production in the US was centered in the Black Belt–and, thus, this area was also where slave labor was most (ab)used. To this day, African Americans constitute a majority in these counties. These counties tend to vote Democrat and show up as a “blue” band within the primary red sea of southern states.

Recognizing a connection between ancient geology and current voting patterns in the South is not new, however. Writing in a 1914 issue of the Bulletin of the American Geographical Society (today called The Geographical Review), Frederick Jackson Turner argues:

“In the lower South. . .the Whig and Democratic areas are strikingly reflective of geological formations. . . [T]he Whig area was practically identical with the chief cotton raising counties, and . . .the most important Whig counties were in the belt where the negro was nearly or quite the majority of the population. Of the counties within the Black Belt (i.e., where the negroes were an actual majority of the population) the Democrats carried but two in Georgia, three in Alabama, and four in Mississippi in three-fourths of these elections. Outside of the chief cotton counties the Whigs carried few counties of the same states. The Democratic counties in the same states for this period were almost entirely in the regions of inferior soils” (pp. 593-594).

Of course, physical geography is not destiny: “there is not absolute geographical control,” writes Turner (p. 595).

Interestingly, Turner also notes that state-level analysis of presidential or state elections is too spatially coarse “to disclose the fact that there are both interstate and intrastate party areas persisting in some cases for many decades or even generations and having clear relations to natural geographic factors” (p. 591). Turner even thinks county-level data is too coarse for analysis!


Turner, F. J. 1914. Geographical influences in American political history. Bulletin of the American Geographical Society 46(8): 591-595.



  1. David says:

    Great blog post!

    Here is an other interesting election map that attempts to better show the distribution of votes via dot density.

  2. Anna Versluis says:

    Thanks, that’s a great map of the election. And I bet Frederick Jackson Turner would like it too!