Cartography of Contagion

We thank our colleague Ed Redmond of the Library’s Geography and Map Division, who originally published this on the Worlds Revealed: Geography & Maps at The Library Of Congress blog. This post caught our eyes first for the visual appeal of the maps and then for the clear and concise commentary and questions about the maps. For additional questions to help students delve into maps, consult the Analyzing Maps teacher’s guide and analysis tool.

Originally published in 1874, these maps of the eastern half of the United States were designed to show the distribution of diseases including typhoid, malaria, pneumonia, tuberculosis, and rheumatism that affected the US population. The maps were published by L.H. Carney, M.D., but we find no biographical data on the author. Medical data (in the form of statistics) is not shown and the maps are simply shaded to show the severity of infection.

The map shown above, interestingly enough, shows the distribution of malarial infections in 1874 in the eastern United States with the exception of the state of West Virginia. For some unknown reason the Mountain State was virtually unaffected in 1874 in the same manner as it was in the early stages of the current 2020 pandemic. Is it an accident of geography? Topography? Or was the area so sparsely inhabited that there were fewer reported infections than in other locations?

Conversely, the map above showing the distribution of phthisis, also known as tuberculosis (red shading), focuses on major population centers rather than the map showing malarial infections (green shading) along major river systems. Even though medical statistics are not provided, one can infer by comparing the two maps that 19th century tuberculosis cases may have been accelerated due to close living conditions in major population centers.

At roughly the same time the above maps were being prepared by commercial publishers the United States Government was producing, in association with “eminent men of science”, statistical atlases from information gathered during the 1870, 1880, and 1890 Census. Each atlas contains statistics, displayed in a graphic form on a map, denoting the approximate number and type of mortal diseases confronting the United States in the late 19th century.

The image below, for example, is from the 1870 Statistical atlas of the United States and provides a graphic illustration of the ratio between deaths from malarial diseases as opposed to all other causes of deaths. The darker the shading translates to a higher number of deaths.

In 1978 the United States issued its last published National Atlas representing demographics and statistics of the nation in the mid 20th century. According to the 1970 Census the number of regular and specialized care hospital beds differed greatly by state. The two atlas plates shown below provide information on the number of hospital beds (general, specialized, and federal) as well as the number of medical professionals in each state.

 

Finally, the maps provided above are intended as a way to use the historical collections of the Library of Congress to help understand the tragic situations that we now face. There will, undoubtedly, be significant statistical information published in the form of maps and digital data forthcoming to help us understand the future spread of disease.