The Geography of Slavery in the United States

I’m aware that similar visuals have been done before, but here, I’m focusing on two metrics: the density of the population (free and slaves), and the percent of the population that is enslaved. To do that, I use a two-color scale, where darkness (or opacity) represents higher density, and color (red) shows a higher percentage of slaves.

Data is from NHGIS, a project of the Minnesota Population Center.