Fort Pitt Museum Pitt, after William Pitt the Elder. As a result, in 1763 local Delawares and Shawnees took part in Pontiac's Rebellion, an effort to drive the British out of their territory. The Indians' siege of Fort Pitt began on June 22, 1763, but the fort was too strong to be taken by force. In negotiations during the siege, the commander of Fort Pitt gave two Delaware emissaries blankets that had been exposed to smallpox, in hopes of infecting the surrounding Indians and ending the siege. The effectiveness of this attempt is unclear. Outbreaks of smallpox had plagued Native Americans for years
Siege of Fort Stanwix surrendered after the Battle of Bemis Heights (second Saratoga). In an analysis after the surrender, Burgoyne noted that the failure of General William Howe to support him made it possible for Washington to divert resources from the area around New York City to assist both in the relief of Stanwix and at Saratoga. Fort Stanwix itself saw little action after the siege, although it was a dangerous and unpopular posting because of regular harassment by Loyalists and hostile Indians. In the spring of 1779 the Continental Army used the fort as a staging ground for the destruction of Onondaga Castle.