A Map of Slavery

Via Matt comes this map, which is genuinely awesome. I initially thought that it was an overlay of density data on an old map, but apparently it was created by Francis Carpenter in 1861. It demonstrates how empty of slaves some parts of the South (Appalachia in particular) were, and consequently why the Confederacy had to deal with so much pro-Union sentiment in those areas. It would be a large (but kind of interesting) project to compare this map with some of the electoral maps at Dave Leip’s website; I fiddled a bit with comparing the 1861 map with the 2004 electoral map, but nothing came of it.