Mortality from Smallpox: The 1780s Epidemic in the Hudson Bay Region

The smallpox epidemic that passed through the Hudson Bay region in 1780-82 is reported to have devastated the native population, causing mortality of 60 to 90 percent. We reassess this claim using three approaches. First we review case-fatality rates from smallpox in more recent, well-documented epidemics; we discuss the nature of smallpox transmission; and we review the possible impact of genetic factors and lifestyle on mortality from smallpox. Second we analyse the volume of trade in the region during the period surrounding the epidemic. Finally we estimate the native population before and after the epidemic. Prior to the 1782 our estimate is based on the carrying capacity of the region, where our focus is on moose, the large ungulate that was the basis of the natives’ survival. The post-epidemic population is based on a backward projection of an early nineteenth-century population count. The three approaches lead broadly to the same conclusion. Mortality from the smallpox outbreak was modest, likely under 20 percent.