Fort Pitt (Pennsylvania) among Native Americans devastated the tribes of Ohio Valley and the Great Lakes areas. On August 1, 1763, most of the American Indians broke off the siege to intercept the approaching force under Colonel Bouquet. In the Battle of Bushy Run, Bouquet fought off the American Indian attack and relieved Fort Pitt on August 10. In 1772, after Pontiac's War, the British commander at Fort Pitt sold the building to two colonists, William Thompson and Alexander Ross. At that time, the Pittsburgh area was claimed by the colonies of both Virginia and Pennsylvania, which struggled for power over the region.
Siege of Fort Pitt McClure would write in his journal, "I was informed at Pittsburgh, that when the Delawares, Shawanese & others, laid siege suddenly and most traitorously to Fort Pitt, in 1764, in a time of peace, the people within, found means of conveying the small pox to them, which was far more destructive than the guns from the walls, or all the artillery of Colonel Boquet's army, which obliged them to abandon the enterprise." 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