Smallpox: The First Bioweapon

By | June 23, 2021

test article image
A transmission electron micrograph of smallpox viruses using a negative stain technique. (Getty Images)

Smallpox is an extremely infectious and deadly disease, wiping out up to 30% of those unlucky enough to catch the virus. By the 1700s, people began figuring out how the disease spread and how to prevent it through inoculation (thanks in large part to an enslaved man named Onesimus), but this opened the door for less scrupulous people to weaponize the virus in times of conflict.

During the Revolutionary War, the British used the knowledge of contagion and inoculation to weaponize smallpox numerous times, especially against people of color. On June 15, 1776, The Virginia Gazette told of such a scheme:

We learn from Gloucester that Lord Dunmore has erected hospitals upon Gwyn's island [sic] and that they are inoculating [black residents] for the smallpox. His lordship, before the departure of the fleet from Norfolk harbour, had two of those wretches inoculated and sent ashore, in order to spread the infection, but was happily prevented.

test article image
British Major General Charles Cornwallis, 1st Marquess Cornwallis (1738–1805). (U.S. Capitol/Wikimedia Commons)

Likewise, famed British General Charles Cornwallis, in his desperate efforts to cling onto those last strands of British control over the colonies, also used black soldiers who had joined the British side with hope of obtaining freedom as bioweapons. During the Battle of Yorktown, Cornwallis sent ailing black soldiers out "in the most deplorable condition, perishing with famine and disease" toward enemy lines to spread the infection to the American army, leaving the Americans the choice to either receive them and be infected or likewise cast them away to die in the field alone.

Of course, the most famous case of intentionally spreading smallpox during wartime is the 1763 incident at Fort Pitt in the heavily contested Ohio country (present-day Pennsylvania), where the British supposedly gave out blankets contaminated with the virus to the Native Americans. Many historians still mark this as the first credible case of biological warfare in world history, although there were rumors of earlier events. In 1757, the Potawatomi suspected the British were willfully at fault for an outbreak that occurred just after the Battle of Lake George. Likewise, in 1770, the Ojibwas accused European fur traders of purposefully infecting them by means of a contaminated flag.