September 6: Benedict Arnold’s Deadly Raid on New London and Groton


Today in Connecticut history marks the anniversary of a horrible homecoming by one of Connecticut’s most infamous native sons — Benedict Arnold.

In early September 1781, the Southern Campaign of the Revolutionary War was in full swing, with major battles waged across Virginia and North and South Carolina earlier in the year. With so much of the Continental Army’s attention focused on the southern states, the British Army — which still maintained headquarters in New York City — found it an opportune time to raid and harass the coastal population of Connecticut, which had been one of the strongest state supporters of the Patriot cause throughout the entire war.

Earlier British coastal raids on Connecticut towns like New Haven and Fairfield were masterminded by William Tryon, a British Major General and Royal Governor of New York, but in September 1781, one of the British Army’s newest generals — Benedict Arnold — was eager to prove himself after defecting the year before. On the morning of September 6th, a combined force of 1,700 British regulars, loyalist soldiers, and Hessian Jaegers landed on each side of the mouth of the Thames River; the western party headed north towards New London while the eastern party marched north to attack Fort Griswold, the large, star-shaped fortification primarily responsible for protecting New London harbor.

This vintage postcard shows the obelisk-style monument and preserved earthworks of Fort Griswold, which was turned into a state park in 1953.

Arnold himself led the western raiding party into New London, where they were met with virtually no resistance as local militia had spread the alarm early enough for most residents to evacuate the city. There, Arnold and his men put the torch to over a hundred homes, businesses, warehouses, and docked ships. Meanwhile, the patriots in Fort Griswold under the command of Colonel William Ledyard put up a valiant defense in what became known as the Battle of Groton Heights — the only major land battle of the American Revolution to take place in Connecticut. Ledyard’s men were ultimately forced to surrender after being overwhelmed by the British attack party’s superior numbers. According to numerous eyewitnesses, the British proceeded to storm the fort and slaughter most of the American soldiers, including Colonel Ledyard, after they had surrendered. In total, 85 out of an estimated 150 – 170 defenders at Fort Griswold were slain before the British spiked the American cannons and returned to their boats.

Even though the Battle of Fort Griswold and simultaneous raid on New London were tactical British victories, Arnold was criticized by his superiors for the high casualty rate incurred by the men under his command (about a quarter of which were killed or wounded) and for the controversial behavior of the British soldiers at Fort Griswold. It would take years for New London to recover from the extensive damage done by Arnold’s raid. Fort Griswold was repaired and used as a military fort until the early 20th century. Today it is operated as a state park, free and open to the public, and contains some of the best-preserved 18th century military earthworks in North America.

A plaque on the monument at Fort Griswold reads: “This monument was erected under the patronage of the State of Connecticut A.D. 1830 and in the 55th year of the Independence of the U.S.A. In memory of the Brave Patriots massacred at Fort Griswold near this spot on the 6th of Sept. AD 1781, when the British, under the command of the Traitor Benedict Arnold, burnt the towns of New London and Groton and spread desolation and woe throughout the region.”

Further Reading

Edward Baker, “Benedict Arnold Turns and Burns New London,” Connecticut Explored

Richard Malley, “Blood on the Hill: The Battle of Groton Heights, September 6, 1781,”

Fort Griswold Battlefield State Park (Official DEEP website)