Arthur Saint Clair, an American general, born in Thurso, Scotland, in 1734, died near Greensburg, Pa., Aug. 31, 1818. He was a grandson of the earl of Roslyn, was educated at the university of Edinburgh, and studied medicine under John Hunter, but entered the army as an ensign, and came to America with Admiral Boscawen. He served under Amherst at Louisburg, and under Wolf at Quebec. In 1762 he resigned his commission, and in 1764 settled in the Ligonier valley, Pennsylvania, where he erected mills, and held several important civil offices. In January, 1776, he was created a colonel in the continental army, and in August a brigadier general, and was in the battles of Trenton and Princeton. In 1777 he was made a major general and commanded Ticonderoga, but was compelled to evacuate it before Burgoyne. For this he was tried by court martial, but acquitted. In 1781 he remained at Philadelphia to protect congress while Washington marched to Yorktown, but joined the main army before Cornwallis surrendered. In 1786 he was sent to congress, of which he became president in 1787. When in 1789 the government of the Northwest territory was organized, he was made governor, and held that post till 1802. In 1791 he became commander-in-chief of the army operating against the Miami Indians. He was surprised on Nov. 4, near the Miami villages, and his force cut to pieces.

Washington refused a court of inquiry, and St. Clair resigned; but congress appointed a committee of investigation, which exonerated him.