Maps Reveal How Slavery Expanded Across the United States

The Smithsonian magazine website has just posted animated maps based on US Census data from 1790-1860 that display the spread of slavery and the increasing density of the US population as well as its western movement. A separate map depicts the dynamics of the free-Black population during this time period. Check out: http://www.smithsonianmag.com/history/maps-reveal-slavery-expanded-across-united-states-180951452/#tYGGBZip32G1C4Gr.99