Army Medical History- Revolutionary War, Smallpox, First Mass Inoculation 1777

Revolutionary War

During the Revolutionary War disease was a major contributor to death in the Continental Army, nearly 90% of soldiers deaths were caused by disease. Smallpox virus was the major contributor. Battle was not just between soldiers but with disease and infection as well. An example of this during the war was when the Continental Army invaded Canada. The goal was to drive British forces from Quebec and convince Canada to bring their province to American colonies. However this mission failed. The main reason? Smallpox. Smallpox was highly contagious and deadly. The death rate of smallpox was approximately 30% (Variola Major strain). Nearly ten thousand soldiers marched to Canada in fall of 1775. Three thousand fell ill with smallpox. Illness was detrimental to the invasion. By spring, half of the soldiers were ill with smallpox and a retreat was ordered.

First Mass Inoculation 1777 

In order to avoid another tragedy like in Canada, George Washington implemented a mass inoculation campaign. The campaign reduced the smallpox mortality in the US Army to less than 2%. At the time smallpox death rate was 15-50%. Inoculation was an early form of vaccination that used live virus. A milder, and sometimes deadly case of the disease was induced in order to build an immunity. Washington’s controversial medical actions, including his decision to inoculate the continental army against smallpox, is credited with assisting with the defeat of the British and America gaining independence.

For more information about the first mass inoculation in the U.S. follow the link here:

The image below in an engraving by James Gillray in 1802. It depicts fear of the mass inoculation to fend off the smallpox virus. It also shows bizarre transformations of people who got the inoculation. Fear of doctors in addition to illness was very common in a time when knowledge of disease and sickness was poor.

Engraving by James Gillray, 1802. Library of Congress