Historical Research Maps: How Your Ancestors Died

By Tyler Moss Premium

As genealogists, we spend a lot of time thinking about how our ancestors lived. But certain resources can teach us something more morbid (but just as important) about our ancestors: how they died. Some maps, like this one, can convey how prevalent various causes of death were in populations.
This map illustrates US consumption deaths based on mortality statistics compiled during the 1870 federal census. Consumption, today more commonly known as tuberculosis, is one of the world’s deadliest diseases. Spread through the air by coughing, spitting and sneezing, it was particularly potent in the late 1800s and early 1900s in impoverished urban areas where people crowded together in places with poor sanitation. Red shading indicates the ratio of total deaths from consumption—the darker the shading, the more consumption deaths. Notice that the New England states suffered especially high losses, along with densely populated hubs of industrialization in places such as Ohio and Illinois. But it’s evident that tuberculosis touched much of the country, and would’ve been a major public health concern of our ancestors at the time.
Part of this map’s significance is its timing: The data was compiled more than a decade before Dr. Robert Koch identified the bacteria that causes the disease, so this disease that killed so many was (tragically) poorly understood at the time. Only once the cause of the contagion was identified in the 1880s could cities begin campaigns to improve sanitation and denounce spitting in public places. Medications to effectively fight the disease wouldn’t be developed until the early 1900s.
The David Rumsey Map Collection contains similar maps that display the prevalence of other deadly diseases in the United States throughout history, including scarlet fever, whooping cough, cancer and malarial fever. Some of the collection’s maps even examine death rates in a particular state, allowing you to drill down. 
Note these maps only show historical trends; you’ll need further research to discover how your specific ancestor died. However, knowing what diseases were likely to kill people in your ancestors’ community might give you insight into how they lived—and how they feared they would die.
A version of this article originally appeared in the May/June 2015 issue of Family Tree Magazine.