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.
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."