The expedition methodically constructed a road across what is now southern Pennsylvania, but was then largely Indian territory. This was in contrast to a similar expedition led by Edward Braddock in 1755 that ended in disaster. Working for most of the summer on the construction of the road, fortifications, and supply depots, the expedition did not come within striking distance of Fort Duquesne until September 1758. In mid September, a reconnaissance force was soundly defeated when its leader, Major James Grant, attempted to capture the fort instead. The French, their supply line from Montreal cut by other British actions, attacked one of the expedition's forward outposts, Fort Ligonier, in an attempt to either drive off the British or acquire further supplies, but were repulsed.
When the expedition neared to within a few miles of Fort Duquesne in mid November, the French abandoned and blew up the fort. Three units of scouts led by Captain Hugh Waddell entered the smoking remnants of the fort under the orders of Colonel George Washington on November 24. General Forbes, who was ill with dysentery for much of the expedition, only briefly visited the ruins. He was returned to Philadelphia in a litter, and died not long afterward.
Cubbison, Douglas R (2010). The British Defeat of the French in Pennsylvania, 1758: A Military History of the Forbes Campaign Against Fort Duquesne. Jefferson, NC: McFarland. ISBN978-0-7864-4739-8. OCLC475664242.
Fowler, William M (2005). Empires at war: The French and Indian War and the Struggle for North America 1754-1763. New York: Walker & Company. ISBN0-8027-1411-0.