Siege of Fort Pitt Siege of Fort Pitt The Siege of Fort Pitt took place during June and July 1763 in what is now the city of Pittsburgh, Pennsylvania, United States. The siege was a part of Pontiac's War, an effort by Native Americans to remove the British from the Ohio Country and Allegheny Plateau after they refused to honor their promises and treaties to leave voluntarily after the defeat of the French. The Native American efforts of diplomacy, and by siege, to remove the British from Fort Pitt ultimately failed. This event is best known as an early instance of biological warfare, where
Illinois campaign the region. When the American Revolutionary War began, in 1775, the Ohio River marked the border between the Illinois Country and Kentucky, an area recently settled by American colonists. The British had originally sought to keep American Indians out of the war, but in 1777 Lieutenant Governor Hamilton received instructions to recruit and arm Indian war parties to raid the Kentucky settlements, opening a western front in the war with the rebel colonists. "From 1777 on," wrote historian Bernard Sheehan, "the line of western settlements was under almost constant assault by white-led [Indian] raiding parties that had originated at Detroit."