Battle of Groton Heights

On September 6, 1781, a modest militia contingent from Connecticut, under the command of Lieutenant Colonel William Ledyard, clashed with a larger British force directed by Brigadier General Benedict Arnold and Lieutenant Colonel Edmund Eyre. This clash has come to be known as the Battle of Groton Heights, though some call it the Battle of Fort Griswold, and it is occasionally referred to by the grimmer label of the Fort Griswold massacre.

Behind this engagement lay a strategic order from Lieutenant General Sir Henry Clinton, who instructed Arnold to strike the port at New London, Connecticut. The purpose was to pull General Washington's attention away from his advance on Cornwallis and his troops stationed in Virginia. Though the raid achieved its broader aim, it met fierce opposition when British troops attempted to seize Fort Griswold, positioned across the Thames River in Groton. New London went up in flames, and a portion of the vessels docked there were destroyed as well, though the majority managed to flee upriver to safety.

The assault on the fort proved costly for the attackers, with several of their commanding officers among the dead or gravely wounded before the walls were finally breached. Once British soldiers pushed inside, the American defenders laid down their arms, yet the shooting did not stop, and a considerable number of those who had surrendered were killed regardless. This heavy toll suffered by British forces throughout the broader campaign against Groton and New London drew sharp rebuke against Arnold from certain officers above him. In the wider context of the war, this stands as the final significant clash fought on northern soil, coming shortly before the far more consequential Franco-American Siege of Yorktown roughly six weeks afterward, an event that would eclipse it in historical memory.

Background

Founded in 1655, Groton began as a section of New London, its neighbor across the Thames River on the northern side of Long Island Sound. The area thrived as a maritime hub, eventually ranking among the busiest ports on New England's coast. In 1705, Groton broke away from New London and became its own incorporated town.

By the time of the Revolutionary War, the combined port of Groton and New London had grown into a key hub for American naval activity, home to privateers who inflicted heavy losses on British merchant vessels. Despite this importance, the harbor's defenses remained weak. On the New London shore stood Fort Trumbull, essentially just a redoubt left exposed on its landward flank. Across the water, Groton's Fort Griswold offered sturdier protection, built in a bastioned, roughly square layout and ringed by a ditch along with additional earthworks outside its walls. Small militia companies, supplemented by a handful of artillery crews, typically manned both installations, and Lieutenant Colonel William Ledyard held overall responsibility for coordinating the region's defense. Chronic shortages plagued both posts. Fort Trumbull remained incomplete, and although Fort Griswold's physical structure was finished, it lacked enough powder, shot, food, and manpower to mount a serious defense if attacked.

By August 1781, Major General George Washington of the Continental Army spotted a chance to move against Lieutenant General Charles Cornwallis and his British troops stationed in Virginia. He began shifting his army southward away from New York, employing various tricks to mislead Lieutenant General Sir Henry Clinton, who commanded British forces in the city. It was not until September 2 that Clinton grasped he had been fooled.

In response, Clinton chose to send a raiding force into Connecticut, hoping to pull Washington's focus back northward. Though conceived primarily as a raid, he also saw potential value in New London as a launching point for deeper operations into New England, provided the British could hold it permanently. Command of this expedition went to Brigadier General Benedict Arnold, who hailed from Norwich, Connecticut, situated just upriver from New London. Once a celebrated general fighting for the American cause, Arnold had defected to the British side the previous September.

Aftermath

Groton and Connecticut had never seen destruction on such a scale, and the clash at Fort Griswold stood as nearly the final triumph for the British before the war's close. Nearly a hundred families found themselves without homes, and nine public buildings along with much of the town's waterfront lay in ruins. By 1792 the state had tallied losses exceeding £61,000, equivalent to $200,000 in Continental currency. To compensate some of those stripped of homes and property, land grants in the Western Reserve were later given out.

Dozens of Americans lost their lives in the struggle at the fort. According to the Groton Gazette, the toll reached roughly 150 casualties. While men like George Middleton managed to flee, others, Stephen Hempstead among them, fell into enemy hands. Hempstead later recalled that following the slaughter, his captors stripped the prisoners of every possession, leaving them with nothing at all. Wounded himself, he described being loaded onto a wagon with fellow injured men bound for the ships waiting offshore. Left to roll unchecked down a slope, the wagon finally crashed into a tree, throwing several occupants clear and worsening their wounds. Arnold, for his part, claimed that eighty five men lay dead within the fort's walls and that sixty more were wounded, most fatally.

In a subsequent account, Arnold put British losses at 48 dead and 145 wounded. Though Clinton commended him for his "spirited conduct," he also voiced concern over the steep price paid, roughly a quarter of the men sent against the fort had been killed or injured. One British witness likened the affair to "a Bunker Hill expedition," and blame for the bloodshed fell on Arnold among many British troops, despite his having no real chance to alter the outcome. Arnold then turned his attention to a proposed strike on Philadelphia, but any hope for that campaign vanished when Cornwallis surrendered at Yorktown in late October.