It isn’t often that a map visually displays a moral issue facing a divided nation and then affects a President’s response. Yet nearly 150 years ago, the U.S. Coast Survey — NOAA’s predecessor organization — produced such a map that, according to historians, President Abraham Lincoln used to coordinate military operations with his emancipation policies.
Created in September 1861, the map entitled “Map showing the distribution of the slave population of the southern states and the United States” is based on statistics from the eighth Census. It is included in NOAA’s new special collection of Civil War maps and charts, “Charting a More Perfect Union,” which contains over 400 documents gathered in one place to mark the 150th anniversary of the Civil War.
“The map was among the first to use shading to represent the human population,” explains retired NOAA Corps Capt. Albert Theberge, the chief of reference for the NOAA Central Library. “It is a prime example of how Coast Survey science aided the Union cause during the Civil War.”
In addition to initiating a trend of statistical cartography, the map’s thematic display of “moral statistics” was revolutionary in affecting political change.
Source: National Oceanic and Atmospheric Administration