Peggy Shippen, wife of the infamous traitor Benedict Arnold, conspired with her husband to undermine the American colonists’ fight for independence from Great Britain.

Who Was Peggy Shippen?

During the American Revolution, Peggy Shippen and her husband, Benedict Arnold, became traitors to the American colonists, sharing with the British confidential information about military strategy. Peggy was long thought to be innocent of any wrongdoing — just another victim of her husband’s deceit — but historians have become convinced that she not only committed treason with Benedict but quite possibly helped initiate the plan.

Early Life

Margaret Shippen, known as Peggy, was born on July 11, 1760, in colonial Philadelphia, the youngest daughter in a wealthy family. Her father was a well-respected lawyer and judge; her mother was the daughter of a prominent lawyer. Among her ancestors were two mayors of Philadelphia. Peggy had three older sisters and an older brother. Two younger brothers died during childhood, leaving Peggy as the youngest in the family.

Marriage to Benedict Arnold

Peggy came of age during the American Revolution, in which she eventually played a significant role. An intelligent, charismatic and beautiful teen, Peggy enjoyed high society. Because of her family’s status, she met influential people, both loyalist (those who supported British rule) and rebel (those who sought American independence). Although the Shippen family tried to remain neutral during the war — Peggy’s father considered it both safer and more financially prudent — the family’s sympathies leaned toward the British.

When the British took control of Philadelphia in 1777, Peggy met John André, a charming, well-educated British officer. Their friendship became the foundation for the treason for which Peggy’s husband, Benedict Arnold, became infamous.

Peggy married Benedict, a widower with three children, on April 8, 1779. He was 38; she was 18. The match was somewhat controversial, in part because Peggy leaned loyalist, while Benedict was an officer in the Continental military; and because he had a reputation as a fiery, impatient man who stood accused of illegal business dealings.

Treason

It was a month after their marriage that Benedict embarked on his career as a traitor to the Continental army. He contacted Peggy’s friend André and offered to provide him with information that would help the British win the war. In exchange, Benedict wanted the British to pay him a large sum of money. Most recent historians believe that Peggy was at the very least complicit in her husband’s treason. More likely, they say, she played a significant role. Their evidence? She, not Benedict, was the one who had been André’s friend; and Benedict’s offer to André came just a month after he and Peggy married.

Through André, Benedict provided information to the British that he — and they — believed would win the war. Benedict had become commander of West Point, a strategic fort on the Hudson River. He passed along news of how many troops were stationed at the fort and when defenses might be weakest. He also did his best to undermine the Americans’ hold on the fort by failing to make needed improvements, using up supplies and sending troops on unnecessary missions. But when André was captured (and executed), Benedict’s treason was uncovered. He fled to New York, which was held by the British, leaving Peggy at their West Point home to face colonial military leaders, including George Washington, by herself.

Aftermath and Death

Peggy’s response was to have what appeared to be a breakdown. Twenty years old and mother of a six-month-old baby, she screamed incoherently and insisted that her husband was gone forever and that someone was trying to kill her baby. Washington and other prominent American leaders sympathized, thinking she was as much a victim of Benedict’s treachery as they themselves were.

Soon after her husband’s defection, Peggy went to live with her family in Philadelphia, but was soon banned from the city. In 1780, she joined Benedict in New York, where she gave birth to their second child on August 28, 1781. In December 1781, they left for London.

In the years before his death in 1801, Benedict traveled to various outposts, including Canada and Guadeloupe in the Caribbean, always trying to make money. Peggy devoted herself to her children — four sons and a daughter — scrambling to ensure their financial well-being before she died of cancer on August 24, 1804. She was 44 years old.