Via reader KT, the Boston Globe picked up on a map comparison of voting patterns this election and cotton agriculture in the antebellum South:
The bottom map dates from 1860 (i.e. the eve of the Civil War), and indicates where cotton was produced at that time.... The top map dates from 2008, and shows the results of the recent presidential election, on county level. ... The pattern of pro-Obama counties in those southern states corresponds strikingly with the cotton-picking areas of the 1860s, especially along the Louisiana-Mississippi and Mississippi-Alabama borders (the pattern corresponds less strikingly and deviates significantly elsewhere).
The link between these two maps is not causal, but correlational, and the correlation is African-Americans.
In related news, the runoff for the Georgia U.S. Senate seat currently held by Saxby Chambliss (R) will go ahead. We'll see.