By: History.com Editors

1779

Benedict Arnold is court-martialed

Published: November 13, 2009

Last Updated: January 31, 2025

The court-martial of Benedict Arnold convenes in Philadelphia, Pennsylvania. After a relatively clean record in the early days of the American Revolution, Arnold was charged with 13 counts of misbehavior, including misusing government wagons and illegally buying and selling goods. Although his notorious betrayal was still many months away, Arnold’s resentment over this order and the perceived mistreatment by the American Army would fuel his traitorous decision.

Abruptly interrupted at its outset by a British attack north of New York City, the court-martial did not get underway again until December 23 in Morristown, New Jersey. Although Arnold was cleared of most charges, General George Washington issued a reprimand against him, and Arnold became increasingly angered.

This Day In History: 09/21/1780 - Benedict Arnold's Betrayal

In this This Day in History video clip, learn about different events that have occurred on September 21. Some of these events include the New York Sun publishes an article and Monday Night Football premieres. Also, the Galileo space probe crashes and Benedict Arnold commits treason.

While on a trip to the important West Point base to make sure that it could withstand a British attack, Arnold stewed over his slight by Washington and the Americans. He thought that he had never been properly rewarded or acknowledged for his military success on their behalf. He began corresponding with British spies about the possibility of changing sides. Arnold negotiated his defection to the British and the subversion of West Point over several months. The British already held control of New York City and believed that by taking West Point they could effectively cut off the Americans' New England forces from the rest of the fledgling nation.

In August 1780, Sir Henry Clinton offered Arnold £20,000 for delivering West Point and 3,000 troops. Arnold told General Washington that West Point was adequately prepared for an attack even though he was busy making sure that it really wasn’t. He even tried to set up General Washington’s capture as a bonus. His plan might have been successful but his message was delivered too late and Washington escaped. The West Point surrender was also foiled when an American colonel ignored Arnold’s order not to fire on an approaching British ship.

Arnold’s defection was revealed to the Americans when British officer John André, acting as a messenger, was robbed by AWOL Americans working as pirates in the woods north of New York City. The notes revealing Arnold’s traitorous agreement were stashed in his boots. Arnold and his wife Peggy, who fooled American officers into believing she had no involvement in the betrayal, escaped to New York City.

At the British surrender at Yorktown, Benedict Arnold was burned in effigy and his name has since become synonymous with traitor. The British didn’t treat him very well after the war either. After prevailing in a libel action, he was awarded only a nominal amount because his reputation was already so tarnished. He died in 1801 and was buried in England without military honors.

Timeline

Also on This Day in History

Discover more of the major events, famous births, notable deaths and everything else history-making that happened on June 1st

About the author

HISTORY.com works with a wide range of writers and editors to create accurate and informative content. All articles are regularly reviewed and updated by the HISTORY.com team. Articles with the “HISTORY.com Editors” byline have been written or edited by the HISTORY.com editors, including Amanda Onion, Missy Sullivan, Matt Mullen and Christian Zapata.

Fact Check

We strive for accuracy and fairness. But if you see something that doesn't look right, click here to contact us! HISTORY reviews and updates its content regularly to ensure it is complete and accurate.

Citation Information

Article title
Benedict Arnold is court-martialed
Website Name
History
Date Accessed
March 23, 2025
Publisher
A&E Television Networks
Last Updated
January 31, 2025
Original Published Date
November 13, 2009

History Every Day

Sign Up for "This Day in History"

Uncover fascinating moments from the past every day! Learn something new with key events in history, from the American Revolution to pop culture, crime and more.

By submitting your information, you agree to receive emails from HISTORY and A+E Global Media. You can opt out at any time. You must be 16 years or older and a resident of the United States.