This very informative infographic shows the power of information visualization in one quick glance.
http://www.southernstudies.org/2013/09/how-slavery-continues-to-shape-southern-politics.html
The slave population, shown in the above map based on the 1860 census, was concentrated in counties where cotton plantations dominated the local economy. Whites in these areas today express more racial resentment and are more likely to vote Republican and oppose affirmative action than other Southerners, a new study finds. (Map from “The Political Legacy of American Slavery.”)
