The Township of St. Clair was named in honor of General Arthur St. Clair, a controversial figure of the 18th century, who came from Scotland in 1755 and settled in the Ligonier Valley. During the Revolutionary War, he rose from Colonel to Major General and was the only Pennsylvanian to become a Major General in the Continental Army. For a time, he commanded Fort Ticonderoga before losing it to the British, for which he was later court-martialed. At the close of the war, he entered the Continental Congress and was its President in 1787. His last days were spent in poverty and obscurity.