Populations and Polarities
Prior to and throughout the war, maps were created to illustrate the division between slave-holding and free states. In some cases, maps provided specific population percentages of slaves within southern states. Often maps merely revealed the division as a binary between the North and the South, starkly illustrating the geography of slavery. In some cases, due to the uncertainty of the war’s outcome, this approach to mapmaking showed up in prominent publications, including the 1857 Atlas by Alexander Keith Johnston. In other cases, maps moved beyond the Mason-Dixon Line, polarizing the division of eastern states with those territories to the West. Different levels of granularity and precision allowed mappers to offer insight into to national, regional, state, and county-level demographics, providing information about a variety of communities and a range of political opinions.
In contrast to these published, widely circulated maps, other maps created to guide fleeing slaves to freedom existed long before the Civil War, but continued to be utilized until emancipation. They conveyed sensitive, and potentially dangerous, information and were available only to a select few. Underground Railroad maps, in particular, indicated “secure” routes and “safe” houses that would enable fleeing slaves to find shelter in northern states and Canada.