The story of the decimation of the Native Americans through contact with Old World infections is well known. Without recourse to notions of divine intervention, both the indigenous South Americans and indeed the conquistadors themselves lacked any explanatory frameworks that could account for the huge numbers of deaths on one side while the other remained untouched. The infection of the South American indigenous populations was accidental, if not unwelcome from the conquistadors’ point of view.

However, there is evidence from the 18th century that European settlers may have deliberately tried to infect Native Americans in North America by giving them blankets believed to be infected with smallpox. How often this primitive biological warfare was undertaken and with what rate of success is unclear. The extent to which Europeans understood how disease would be spread to the Native Americans is uncertain, and as in the South American case, it was more likely the accidental contact of two peoples with different patterns of immunity that wreaked such widespread damage (Kraut, 1994).