Fort Ligonier was an active British army fort through the conclusion of the French and Indian War in 1763 and during the pan-Indian uprising known as Pontiac’s War (1763-1765). After the successful conclusion to the Forbes Campaign in November of 1758, construction of the new British Fort Pitt at the site of Fort Duquesne began.
Fort Ligonier’s garrison began to shrink in numbers as Fort Pitt became the dominant fortification along the western frontier. By 1766, Fort Ligonier was decommissioned by the British army and a settlement had begun to rise around the remains of the fort. Fort Ligonier was active until 1766 when Arthur St. Clair became its civil caretaker. During the American Revolution a new fort, Fort Preservation, was built for settlers seeking refuge from American Indian raids. Both forts quickly fell into ruin.