Arthur St. Clair

Arthur St. Clair had a long military career spanning from service in Seven Years’ War, in the Continental Army, and later the United States Army. In the American Revolution, he rose to the rank of Major General, and was an aide-de-camp to George Washington. He later served as governor of the Northwest Territory.

Early Life

Arthur St. Clair was born in Caithness, Scotland in 1734. He was educated at the University of Edinburgh before being commissioned as an officer in the British military to serve in North America. He was a part of the British capture of Quebec City. After the Seven Years’ War, he married Phoebe Bayard and purchased land in Pennsylvania. He was involved in local politics as a magistrate.

Service in the American Revolution 

St. Clair was commissioned in the Continental Army. After failing to capture Quebec in late 1775, he was stationed at headquarters in Trenton, New Jersey to assist in the training of troops. He crossed the Delaware with the Continental Army and was a part of the Battle of Trenton. He is believed to have assisted Washington in developing the strategy for American victory at the Battle of Princeton. While most officers advocated a retreat, St. Clair offered a bold idea. St. Clair argued that the army should head for Princeton, outflank the British on the way, and capture the town. Washington's army followed St. Clair's plan and defeated the British at Princeton the following morning.

In response to the success at Princeton, St. Clair was given command of Fort Ticonderoga in April of 1777.¹ In July 1777, Washington defended his colleague after he lost Fort Ticonderoga to the British during the Saratoga Campaign. Washington asked him to join his staff as an aide-de-camp after a court martial cleared him of any wrongdoing.

In November 1781, following his involvement in the British surrender at the Battle of Yorktown, Washington ordered St. Clair, who was serving as a Major General, to lead the Pennsylvania Line into the Carolinas to help Nathanael Greene expel the British.

Governor of the Northwest Territory and Service in the U.S. Army

In 1787, St. Clair was appointed as the governor of the Northwest Territory. During his tenure, he lived in and name Cincinnati, Ohio after the Society of Cincinnati. He created written laws for the territory and attempted to resolve conflict with Native Americans groups such as the Shawnee, Delaware, and Ojibwe nations being displaced by American settlers.

As president, Washington appointed him as the commander of the American army assigned to conflicts with Native American conflicts north of the Ohio in 1791. St. Clair led men without proper military experience or training deep into the woods of western Ohio. On the morning of November 4, 1791, members of the Miami and Shawnee nations attacked, killing or wounding over 600 of St. Clair's soldiers, including most of his officers. St. Clair and a few hundred men escaped back to Fort Washington on the banks of the Ohio River. The loss was known as “St. Clair’s Defeat.”

His failures in the Northwest Territory led to the first investigation of the executive branch by the legislature under the Constitution in January 1792. Amid the investigation, St. Clair wrote to Washington, “A Wish to rectify the public Opinion, and a Duty that, I conceive I owe to myself, induces me to request that an Enquiry into my Conduct may be instituted—When that is over I may hope to be permitted to resign the Commission of Major General which I now hold.”² St. Clair was exonerated, but he was replaced from his military post. Washington allowed him to remain as the Governor of the Ohio Territory.

Retirement from Public Life

In 1802, President Thomas Jefferson removed St. Clair from his territorial governorship, preferring a member of his own party rather than a Federalist. St. Clair spent the rest of his life in western Pennsylvania, struggling financially. He died in 1818 at 81 years of age.

Mary Stockwell, Ph.D., revised by Zoie Horecny, Ph.D., 9 April 2025

Notes:

1. “Orders to Major General Arthur St. Clair, 9 April 1777,” Founders Online, National Archives.

2. “To George Washington from Arthur St. Clair, 26 March 1792,” Founders Online, National Archives.

Bibliography:

Fischer, David Hackett. Washington's Crossing. Oxford and New York: Oxford University Press, 2004.

The Life and Public Services of Arthur St. Clair, Volumes 1 and 2. Ed. William Henry Smith. Cincinnati: Robert Clarke & Company, 1882.

Rush, Richard. Washington in Domestic Life: From Original Letters and Manuscripts. Philadelphia: J. B. Lippincott and Co. 1857.