Fort Trumbull



Battle Summary
Details Stats Colonists/Allies British/Allies
Name: Battle of Groton Heights Total Forces: 160 1700
Date(s): 09/06/1781 Killed: 85 48
Location: Groton, Connecticut Wounded: 60 145
Duration (days): 1 Captured:
Victory: British Total Ships:
Col./Ally Cmdr.: William Ledyard Ships Lost:
Brit./Ally Cmdr.: Benedict Arnold Ships Captured:


The Battle of Groton Heights (also known as the Battle of Fort Griswold, and occasionally called the Fort Griswold massacre) was a battle of the American Revolutionary War fought on September 6, 1781, between a small Connecticut militia force led by Lieutenant Colonel William Ledyard and the more numerous British forces led by Brigadier General Benedict Arnold and Lieutenant Colonel Edmund Eyre.

In an unsuccessful attempt to divert General George Washington from marching against Lord Cornwallis’s army in Virginia, Lieutenant General Sir Henry Clinton ordered General Arnold to raid the Connecticut port of New London. Although the raid was a success, the Connecticut militia stubbornly resisted British attempts to capture Fort Griswold, across the Thames River in Groton.

Several leaders of the attacking British force were killed or seriously wounded, and much of the defending garrison was either killed, mortally wounded, or captured when the fort was stormed. High British casualties lead to criticism of General Arnold by some of his superiors. The battle was the last major military encounter of the war in the northern United States, preceding the decisive American victory at Yorktown, Virginia, by about six weeks.


With its history dating back to 1655, Groton, Connecticut was originally a part of New London, its larger counterpart on the other side of the Thames River on the northern shore of Long Island Sound. Groton was an important maritime port, and became one of the largest along the New England coastline. Groton officially separated from New London and incorporated as a separate town in 1705. During the American Revolutionary War, the port was a major center of rebel naval operations, including highly successful privateering operations against British shipping. The port, however, was comparatively poorly protected: Fort Trumbull, on the New London side, was little more than a redoubt open on the inland side, while Fort Griswold in Groton was a more substantial, roughly square, bastioned stone fort surrounded by a ditch and some outer earthen defenses. They were typically garrisoned by small companies of militia, including a few artillerymen, and overall command of the area’s defenses was directed by Lieutenant Colonel William Ledyard. The forts suffered from continuous shortages of provisions and equipment. In the case of Fort Trumbull, the fort itself was unfinished. Although Fort Griswold’s infrastructure was complete, it lacked sufficient gunpowder, cannonballs, food, and troops to conduct an effective stand against the British.

In August 1781, Continental Army Major General George Washington realized there was an opportunity to strike at the British army of Lieutenant General Charles, Earl Cornwallis, in Virginia. Using a variety of strategems to deceive the British Commander-in-Chief and head of the British forces in New York City, Lieutenant General Sir Henry Clinton, Washington began moving his forces south from the New York area. General Clinton realized on September 2 that he had been deceived. Unable to mobilize quickly enough to assist Cornwallis, and unwilling to detach a large percentage of his forces in the face of the Continental forces Washington had left around New York, Clinton decided to launch a raid into Connecticut in an effort to draw Washington’s attention. Though Clinton only planned it as a raid, he also believed that if a permanent British occupation of New London could be established, it could be used as a base for further operations into the interior of New England. He gave command of the forces for the raid to Norwich, Connecticut native Brigadier General Benedict Arnold, who had changed sides the previous September.


The forces assembled by the British were divided into two battalions, numbering about 1,700 men. The first, under Lieutenant Colonel Edmund Eyre, was composed of the 40th and 54th Regiments of Foot and a Loyalist provincial regiment, Cortlandt Skinner’s New Jersey Volunteers. The second battalion, under Arnold’s command, consisted of the 38th Foot and a variety of Loyalist units, including the Loyal American Regiment and Arnold’s provincial regiment, known as the American Legion. The expedition also included about 100 Hessian jägers, a small number of artillerymen, three six-pound guns, and a howitzer, all of which were divided between the battalions. These troops were embarked on transports, and sailed on September 4 in the company of a fleet of smaller armed ships led by Commodore John Bazely in the fifth-rate {HMS|Amphion|1780|6}.

The fleet anchored about {convert|30|mi|km} west of New London to make final preparations, and then sailed for New London late on September 5, intending to make a nighttime landing. However, contrary winds prevented the transports from reaching the port until it was already daylight on September 6. In the early hours of that morning Rufus Avery, a colonial officer stationed at Fort Griswold, witnessed the fleet’s arrival:

“…about three o’clock in the morning, as soon as I had daylight so as to see the fleet, it appeared a short distance below the lighthouse. The fleet consisted of thirty-two vessels … I immediately sent word to Captain William Latham, who commanded [Fort Griswold], and who was not far distant. He very soon came to the fort, and saw the enemy’s fleet, and immediately sent a notice to Col. William Ledyard, who was commander of the harbor, Fort Griswold, and Fort Trumbull.”

Upon receiving the alert, Ledyard sent a messenger to notify Governor Jonathan Trumbull and local militia leaders of the British arrival, and went to Fort Griswold to arrange its defenses. Fort Griswold’s guns were fired twice, a signal of enemy approach. However, one of the British ships fired a third round, changing the meaning of the signal to indicate the arrival of a victorious friend. This signal confusion led to delays in the mustering of militia companies.

At sunrise on September 6, the British landed on both sides of the mouth of the Thames River. The people of the town could do nothing but evacuate, and several ships in the harbor escaped upstream. The 800-man detachment that Arnold led in New London met with no resistance. The defenders of Fort Trumbull, 23 men led by Captain Shapley, following orders left by Colonel Ledyard, fired a single volley, spiked the guns, and boarded boats to cross the river to Fort Griswold. Seven of Shapley’s men were wounded, and one of the boats was captured; the detachment Arnold sent to take Fort Trumbull lost, according to Arnold’s account, four or five killed or wounded. Arnold’s troops continued into the town, where they set about destroying stockpiles of goods and naval stores. Under the orders given, much of the town was supposed to be spared; but unknown to Arnold, at least one of the storehouses burned contained a large quantity of gunpowder. When it ignited, the resulting explosion set fire to the surrounding buildings. The fire was soon uncontrollable and 143 buildings were consumed by flames. Several ships in the harbor were able to escape upriver when the wind changed.

Meanwhile, Lieutenant Colonel Eyre’s force of 800 men that landed on the east side of the Thames River was slowed by tangled woodlands and swamplands. The New Jersey Loyalists landed after the initial wave of regulars, also delayed by the difficulty in moving the artillery through rough conditions, and did not participate in the assault.

George Middleton, a boy of 12 (who in some accounts is incorrectly confused with George Middleton, the commanding officer of an African American militia unit called the Bucks of America) witnessed the quick rallying of Ledyard’s militia and the landing of the British regiments, which he reported occurred between 10:30 and 11:00 am:

“The other division of troops landed on the east side of the river … under the command of Col. Eyre and Major Montgomery. This division … got to the terminus of the woods … a little south of east on a direct line from the fort. Here the division halted, and Major Montgomery sent Captain Beckwith with a flag to the fort to demand its surrender. Colonel Ledyard … sent a flag and met Beckwith … The bearer of the American flag answered, ‘Colonel Ledyard will maintain the fort to the last extremity.'” Eyre sent a second parley flag, threatening to give no quarter if the militia did not surrender. Ledyard’s response was as before, even though some of his subordinates argued that they should leave the fort and fight outside it.

General Arnold ordered Eyre to assault the fort, believing the fort would fall easily. However, upon reaching a prominence from which he could see its defenses, Arnold realized that the fort was more complete than anticipated and that taking it would not be easy. Since one of the reasons for taking the fort was to prevent the escape of boats upriver, and many had already passed beyond the fort, Arnold attempted to recall Eyre, but the battle was joined a few minutes before the messenger arrived.


On the return of the second parley flag, Eyre launched a full scale assault upon the fort and its roughly 150 defenders. Stephen Hempstead, a sergeant in Ledyard’s militia recounted, “When the answer to their demand had been returned … the enemy were soon in motion, and marched with great rapidity, in a solid column … they rushed furiously and simultaneously to the assault of the southwest bastion and the opposite sides.” As the British neared the ditch, they were met by a bombardment of grapeshot that killed and wounded many. This briefly scattered the British, who reformed into two units. Eyre led one force against the southwest bastion, where American fire repulsed the assault, seriously wounding Eyre and several of his officers. (New London historian Frances Manwaring Caulkins’ assertion that Eyre was mortally wounded is apparently incorrect; Arnold reported that Eyre survived.) Major William Montgomery led the second party to an abandoned redoubt just east of the fort. From there they moved across the ditch and assaulted the ramparts. Against fierce resistance this unit gained the bastion, but Montgomery was instantly killed by a bayonet thrust. Montgomery’s men were finally able to open a gate from inside, and the British force poured into the fort. Seeing that the fort was penetrated, Colonel Ledyard ordered a cease fire and prepared to surrender the place.

What happened next was a subject of some controversy. The most detailed extant accounts of the event are from American sources, but are fairly consistent in what they describe. According to these accounts, the British continued to fire on the Americans despite Ledyard’s signs of surrender, and much of the garrison was consequently either killed or seriously wounded. Rufus Avery wrote in his account, “I believe there was not less than five or six hundred men of the enemy on the parade in the fort. They killed and wounded nearly every man in the fort as quick as they could…” Jonathan Rathbun described the cold-blooded killing of Colonel Ledyard with his own sword by an officer:

“… the wretch who murdered him [Ledyard], exclaimed, as he came near, ‘Who commands this fort?’ Ledyard handsomely replied, ‘I did, but you do now’, at the same moment handing him his sword, which the unfeeling villain buried in his breast! Oh, the hellish spite and madness of a man that will murder a reasonable and noble-hearted officer, in the act of submitting and surrendering!”

Some accounts claim that Captain George Beckwith killed Colonel Ledyard, while others claim it was Captain Stephen Bromfield, who assumed command after Major Montgomery was killed. Stephen Hempstead recalled the bloody scene in the aftermath: “Never was a scene of more brutal wanton carnage witnessed than now took place. The enemy were still firing upon us … [until] they discovered they were in danger of being blown up…” Rufus Avery believed the attack was called off due to the chance that further musket fire might set off the fort’s powder magazine.

American accounts and historical descriptions ascribe several possible reasons for the British behavior. During the battle, the fort’s flag was supposedly shot down at one point. Although it was quickly reraised, some of the British attackers interpreted the event as striking the colors, making a sign of surrender; the British suffered significant casualties when they then approached the fort on that occasion. Combined with anger over the death and wounding of their commanding officers, this led them to disregard Ledyard’s legitimate surrender. Some accounts also claim that Americans in one part of the fort were unaware that Ledyard had surrendered, and continued to fight, leading the British to also continue fighting, even against those who had surrendered.

Early British historians generally did not report much beyond Arnold’s report of the expedition, which did not mention killings after the surrender. William Gordon, however, reported in his 1788 history of the war that “[t]he Americans had not more than a half dozen killed” before the fort was stormed, and that “a severe execution took place after resistance ceased.” An Italian historian wrote in 1809 that “[t]he assailants massacred as well those who surrendered as those who resisted.”


The massacre at Fort Griswold marked one of the largest tragedies in the history of Groton and Connecticut, and was one of the last British victories in North America before the end of the war. Damage to New London was substantial: one estimate placed the value destroyed at nearly $500,000. The battle left nearly 100 families homeless, destroyed nine public buildings, and much of the town’s waterfront. The state in 1792 identified losses that totaled more than £61,000, or $200,000 Continental dollars. Some who lost homes or property were awarded land in the Western Reserve.

The slaughter at Fort Griswold left dozens of Americans dead. The Groton Gazette reported that casualties numbered about 150. Some survivors, such as George Middleton, escaped, but others, including Stephen Hempstead, were taken prisoner. He stated, “After the massacre, they plundered us of everything we had, and left us literally naked…” Hempstead, who was among the wounded, reported how he was placed on a wagon with others to be taken down to the fleet. The wagon was allowed to run down the hill, where it stopped when it struck a tree, throwing some of the men off the wagon and aggravating their injuries. General Arnold reported that 85 men “…were found dead in Fort Griswold, and sixty wounded, most of them mortally.”

Benedict Arnold later issued a report stating that 48 British soldiers were killed and 145 wounded. General Clinton praised Arnold for his “spirited conduct”, but also complained about the high casualty rate; about 25 percent of the troops sent against Fort Griswold were killed or wounded. One British observer wrote that it had been like “a Bunker Hill expedition,” and many British soldiers blamed Arnold for the events at Fort Griswold, even though he had not been in a position to prevent the reported slaughter. Arnold next proposed a raiding expedition against Philadelphia, but the surrender of General Charles Cornwallis at Yorktown in late October ended that idea.


Although the British left a burning powder trail to destroy Fort Griswold’s magazine, a daring militiaman entered the fort and extinguished the fire. Both Forts Trumbull and Griswold were extensively modified in the 19th century, and are now preserved in state parks. The Fort Griswold park also includes the Groton Monument, erected in the 1820s to commemorate the battle. Both forts are listed on the National Register of Historic Places.