Smallpox: The First Bioweapon
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.