Fort McIntosh Fort McIntosh at the site of present-day Beaver, Pennsylvania, was built by General Lachlan McIntosh in 1778 as a staging ground for a planned military expedition in the west. Although the expedition was soon abandoned, Fort McIntosh remained occupied until 1785. Fort Pitt Fort Pitt was the Gateway to the West at the forks of the Ohio River Valley. Built in 1759 on the ruins of French Fort Duquesne, it served as an outpost for the British from 1759-1772. Occupied by the Americans, first by Virginian forces in 1773, then by troops of the Continental Army in 1777, Fort Pitt...