The siege of Fort Mifflin or siege of Mud Island Fort from September 26 to November 16, 1777 saw British land batteries commanded by
Captain
Captain is a title, an appellative for the commanding officer of a military unit; the supreme leader of a navy ship, merchant ship, aeroplane, spacecraft, or other vessel; or the commander of a port, fire or police department, election precinct, e ...
John Montresor
Captain John Montresor (22 April 1736 – June 1799) was a British military engineer and cartographer in North America.
Early life
Born in Gibraltar 22 April 1736 to British military engineer James Gabriel Montresor and his first wife, Mary ...
and a British naval squadron under
Vice Admiral Lord Richard Howe attempt to capture an American fort in the
Delaware River
The Delaware River is a major river in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. From the meeting of its branches in Hancock (village), New York, Hancock, New York, the river flows for along the borders of N ...
commanded by
Lieutenant Colonel
Lieutenant colonel ( , ) is a rank of commissioned officers in the armies, most marine forces and some air forces of the world, above a major and below a colonel. Several police forces in the United States use the rank of lieutenant colone ...
Samuel Smith. The operation finally succeeded when the wounded Smith's successor,
Major
Major (commandant in certain jurisdictions) is a military rank of commissioned officer status, with corresponding ranks existing in many military forces throughout the world. When used unhyphenated and in conjunction with no other indicators ...
Simeon Thayer
Simeon Thayer (April 30, 1737 – October 14, 1800) fought in Rogers' Rangers during the French and Indian War and made a harrowing escape from French-allied Indians. At the outbreak of the American Revolutionary War, the Rhode Island assembly ...
, evacuated the fort on the night of November 15 and the British occupied the place the following morning. Owing to a shift of the river,
Fort Mifflin
Fort Mifflin, originally called Fort Island Battery and also known as Mud Island Fort, was commissioned in 1771 and sits on Mud Island (or Deep Water Island) on the Delaware River below Philadelphia, Pennsylvania near Philadelphia International A ...
is currently located on the north bank of the Delaware adjacent to
Philadelphia International Airport
Philadelphia International Airport is the primary airport serving Philadelphia, Pennsylvania. The airport served 19.6 million passengers annually in 2021, making it the 21st busiest airport in the United States. The airport is located from t ...
.
After General
Sir William Howe's British-Hessian army occupied
Philadelphia, Pennsylvania
Philadelphia, often called Philly, is the largest city in the Commonwealth of Pennsylvania, the sixth-largest city in the U.S., the second-largest city in both the Northeast megalopolis and Mid-Atlantic regions after New York City. Sinc ...
on September 26, 1777, it became necessary to supply his troops. Fort Mifflin on Mud Island in the middle of the Delaware and
Fort Mercer
Fort Mercer was a earthen fort on the Delaware River on its New Jersey shore constructed by the Continental Army during the American Revolutionary War. Built by Polish engineer Thaddeus Kosciuszko under the command of George Washington, Fort Me ...
at
Red Bank, New Jersey
Red Bank is a borough in Monmouth County, New Jersey, United States. Incorporated in 1908, the community is on the Navesink River, the area's original transportation route to the ocean and other ports. Red Bank is in the New York Metropolitan A ...
, together with river obstructions and a small flotilla under
Commodore
Commodore may refer to:
Ranks
* Commodore (rank), a naval rank
** Commodore (Royal Navy), in the United Kingdom
** Commodore (United States)
** Commodore (Canada)
** Commodore (Finland)
** Commodore (Germany) or ''Kommodore''
* Air commodore ...
John Hazelwood
John Hazelwood (1726 – March 1, 1800) served as a Commodore (rank), Commodore in the Pennsylvania Navy and Continental Navy and was among the most noted naval officers during the American Revolutionary War. Born in England about 1726, he ...
prevented the
Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against F ...
from shipping provisions into the city. With Philadelphia effectively blockaded by the Americans, the Howe brothers were forced to lay siege to Fort Mifflin in order to clear the river.
A Hessian attempt to storm Fort Mercer failed with heavy losses on October 22 in the
Battle of Red Bank
The Battle of Red Bank was a battle fought on October 22, 1777 during the American Revolutionary War in which a British and Hessian force was sent to take Fort Mercer on the left bank (or New Jersey side) of the Delaware River just south of Phil ...
. Two British warships which had run aground near Mud Island were destroyed the next day.
General
George Washington
George Washington (February 22, 1732, 1799) was an American military officer, statesman, and Founding Father who served as the first president of the United States from 1789 to 1797. Appointed by the Continental Congress as commander of th ...
reinforced Fort Mifflin throughout the siege, but the garrison never numbered more than 500 men. After a few setbacks, the British finally assembled enough artillery and warships to bring Fort Mifflin under an intense bombardment beginning on November 10. No longer able to reply to the British bombardment, Thayer ordered the survivors to row across to New Jersey in the night and left the flag flying. Fort Mercer was abandoned soon afterward, opening the Delaware and permitting the British to hold Philadelphia until June 1778.
Background
![Fort Mifflin flag](https://upload.wikimedia.org/wikipedia/commons/5/5b/Fort_Mifflin_flag.jpg)
After the British defeated the American army at the
Battle of Brandywine
The Battle of Brandywine, also known as the Battle of Brandywine Creek, was fought between the American Continental Army of General George Washington and the British Army of General Sir William Howe on September 11, 1777, as part of the Ame ...
on September 11, 1777, Howe failed to follow up Washington's withdrawal to
Chester, Pennsylvania
Chester is a city in Delaware County, Pennsylvania, United States. Located within the Philadelphia Metropolitan Area, it is the only city in Delaware County and had a population of 32,605 as of the 2020 census.
Incorporated in 1682, Chester is ...
. From that town on the Delaware, the Americans marched northeast through
Darby to cross the
Schuylkill River
The Schuylkill River ( , ) is a river running northwest to southeast in eastern Pennsylvania. The river was improved by navigations into the Schuylkill Canal, and several of its tributaries drain major parts of Pennsylvania's Coal Region. It fl ...
at the Middle Ferry. From the ferry, the army moved north to present-day
East Falls
East Falls (also The Falls, formerly the Falls of Schuylkill) is a neighborhood in the Northwest section of Philadelphia, Pennsylvania, in the United States. It lies on the east bank of the "Falls of the Schuylkill," cataracts submerged in 1 ...
and went into camp. For the next ten days, the two armies sparred while the British won the
Battle of Paoli
The Battle of Paoli (also known as the Battle of Paoli Tavern or the Paoli Massacre) was a battle in the Philadelphia campaign of the American Revolutionary War fought on September 20, 1777, in the area surrounding present-day Malvern, Pennsylva ...
and several skirmishes. On the night of September 22, Howe outmaneuvered Washington and won an unopposed crossing of the Schuylkill near
Valley Forge
Valley Forge functioned as the third of eight winter encampments for the Continental Army's main body, commanded by General George Washington, during the American Revolutionary War. In September 1777, Congress fled Philadelphia to escape the B ...
. On September 26, the British army occupied the rebel capital of Philadelphia. In the face of the British advance the
Second Continental Congress
The Second Continental Congress was a late-18th-century meeting of delegates from the Thirteen Colonies that united in support of the American Revolutionary War. The Congress was creating a new country it first named "United Colonies" and in 1 ...
fled first to
Lancaster then to
York, Pennsylvania
York ( Pennsylvania Dutch: ''Yarrick''), known as the White Rose City (after the symbol of the House of York), is the county seat of York County, Pennsylvania, United States. It is located in the south-central region of the state. The populati ...
.
[Dupuy & Dupuy, 715]
During the summer of 1777,
Philippe Charles Tronson du Coudray
Philippe Charles Jean Baptiste Tronson du Coudray (September 8, 1738 – September 11, 1777) was a French army officer who volunteered for service in the Continental Army during the American Revolutionary War.
Early life
Born in Reims, France, ...
, a French artillery expert, arrived from France. Congress appointed him a major general and inspector general of ordnance, and Washington assigned him the task of strengthening Philadelphia's river defenses. His aristocratic airs soon irritated people. He began to quarrel with another French military engineer,
Louis Lebègue Duportail
Louis Antoine Jean Le Bègue de Presle Duportail (; 14 May 1743 – 12 August 1802) was a French military leader who served as a volunteer and the Chief Engineer of the Continental Army during the American Revolutionary War. He also served a ...
, about how the defenses were to be prepared and even managed to anger
Gilbert Motier, marquis de La Fayette. To the relief of many, Coudray drowned on September 16 after he foolishly rode his horse onto a Schuylkill ferry and the animal leaped into the river.
The Mud Island Fort was designed and begun by British engineer Captain
John Montresor
Captain John Montresor (22 April 1736 – June 1799) was a British military engineer and cartographer in North America.
Early life
Born in Gibraltar 22 April 1736 to British military engineer James Gabriel Montresor and his first wife, Mary ...
in 1771. The river front was shielded by a stone face, but then the work stopped due to a shortage of money. After the outbreak of war with Britain, the rest of the fort's defenses were completed with wooden palisades and earthen ramparts, despite the infighting among the French engineer officers. There were wooden barracks for the enlisted men along the west and north sides of the fort. Nearby was a two-story building to accommodate officers. According to one of the defending soldiers, a battery of 18-pound artillery pieces stood at the southeast end of Mud Island. On the southwest end, one 32-pound and four or five 12-pound and 18-pound cannons guarded the river. Three 12-pound guns covered the northwest end of the island.
[McGuire, 183] Another account states that ten 18-pound guns made up the main battery while each of the four blockhouses contained four cannons.
[Boatner, 384] A bristling set of sharpened logs surrounded the fort while the low ground along the shoreline was infested with ''
trous-de-loups'' or wolf holes.
Chevaux de frise
The ''cheval de frise'' (plural: ''chevaux de frise'' , "Frisian horses") is a defensive obstacle, which existed in a number of forms and were employed in various applications. These included underwater constructions used to prevent the passa ...
prevented the British navy from ascending the Delaware. Their iron tipped stakes threatened to tear the bottom out of any ship whose master was reckless enough to make the attempt.
Siege
Preparations
Colonel
Lewis Nicola
Lewis Nicola (1717 – August 9, 1807) was an Irish-born American military officer, merchant, and writer who held various military and civilian positions throughout his career. Nicola is most notable for authoring the Newburgh letter, which ...
held Fort Mifflin with a party of Pennsylvania militia, mostly men untrained for field service.
[McGuire, 184] Among the approximately 60 militiamen present for duty, not a single one knew how to operate the cannons. On September 23, with Philadelphia about to be captured, Washington sent Lieutenant Colonel
Samuel Smith of the
4th Maryland Regiment with a detachment of
Continentals into the fort on Mud Island. Smith's force numbered 200 soldiers plus Major Robert Ballard of Virginia, Major
Simeon Thayer
Simeon Thayer (April 30, 1737 – October 14, 1800) fought in Rogers' Rangers during the French and Indian War and made a harrowing escape from French-allied Indians. At the outbreak of the American Revolutionary War, the Rhode Island assembly ...
of Rhode Island, and Captain Samuel Treat of the Continental Artillery.
[ However, another account stated that Thayer did not reach Fort Mifflin until October 19.][Thayer & Stone, 75] With the British army closing in on Philadelphia, the small force had to reach Fort Mifflin by a circuitous route. On the last leg of their journey, reinforcements for Mud Island had to be ferried across the Delaware from Red Bank, New Jersey
Red Bank is a borough in Monmouth County, New Jersey, United States. Incorporated in 1908, the community is on the Navesink River, the area's original transportation route to the ocean and other ports. Red Bank is in the New York Metropolitan A ...
under the protection of the Pennsylvania Navy
The Pennsylvania Navy (more formally known as the Pennsylvania State Navy or in modern terms the Pennsylvania Naval Militia) served as the naval force of Pennsylvania during the American Revolution and afterward, until the formation of the United ...
river flotilla commanded by John Hazelwood
John Hazelwood (1726 – March 1, 1800) served as a Commodore (rank), Commodore in the Pennsylvania Navy and Continental Navy and was among the most noted naval officers during the American Revolutionary War. Born in England about 1726, he ...
.[ Washington ordered Colonel the Baron Henry Leonard d'Arendt, a six-foot tall Prussian to take charge of Fort Mifflin. Since the baron was too sick to assume his post, Smith became the effective commander.][McGuire, 185] To further complicate matters, Lieutenant Colonel John Green of the 7th Virginia Regiment
The 7th Virginia Regiment was raised on January 11, 1776, at Gloucester, Virginia, for service with the Continental Army. The regiment would see action at the Battle of Brandywine, Battle of Germantown (after which it wintered at Valley Forge), B ...
, who outranked Smith, arrived with reinforcements on October 18. Smith developed an uneasy relationship with Hazelwood and their differences soon became obvious. On October 4, Washington marched against Howe's army at the Battle of Germantown
The Battle of Germantown was a major engagement in the Philadelphia campaign of the American Revolutionary War. It was fought on October 4, 1777, at Germantown, Pennsylvania, between the British Army led by Sir William Howe, and the American Con ...
but was defeated.[
To deny the British the use of Province and Carpenter's Islands, the Americans broke the riverside dikes. This act forced their enemies to build their batteries on top of the dikes and to labor in knee-deep water. As an example of the difficulties involved, the British lost an 8-inch howitzer and a soldier drowned when the craft carrying the gun sank in the Schuylkill. On the night of October 10, Captain ]John Montresor
Captain John Montresor (22 April 1736 – June 1799) was a British military engineer and cartographer in North America.
Early life
Born in Gibraltar 22 April 1736 to British military engineer James Gabriel Montresor and his first wife, Mary ...
had his crews begin work on a battery on Carpenter's Island, opposite the fort. At this time, the British already had constructed a two gun battery near the mouth of the Schuylkill River
The Schuylkill River ( , ) is a river running northwest to southeast in eastern Pennsylvania. The river was improved by navigations into the Schuylkill Canal, and several of its tributaries drain major parts of Pennsylvania's Coal Region. It fl ...
. On the 11th, Hazelwood and Smith launched a joint attack by row galleys on the working parties. After losing one man killed and one wounded, a total of two officers and 56 enlisted men from the 1st Grenadier Battalion waved the white flag. The prisoners were quickly herded into the Americans' boats before engineer Captain James Moncrieffe could arrive with a rescue party of Hessians. The British court martialed two officers for this setback.
On October 14, French engineer Major François-Louis Teissèdre de Fleury came to the fort and proved a great help to Smith.[ Fleury, who had come to America with Du Coudray, set about improving the defenses. He built a firing step for the soldiers to fire over the palisades, a redan to support the main battery, constructed a last-stand redoubt at the fort's center, and corrected some of the fort's shortcomings. ]Thomas Paine
Thomas Paine (born Thomas Pain; – In the contemporary record as noted by Conway, Paine's birth date is given as January 29, 1736–37. Common practice was to use a dash or a slash to separate the old-style year from the new-style year. In th ...
visited the fort on the 15th and observed that 30 enemy shells fell into the fort that day. On October 20, a British red-hot shot set off a minor explosion in the northwest blockhouse. Baron d'Arendt finally came to assume command on the 21st. While taking the Prussian on a tour of the fort, Smith and Fleury watched with shock and contempt as the terrified man ran away from the damaged blockhouse. D'Arendt announced that the fort was indefensible and left Mud Island for good on October 27, pleading "illness".[Dorwart, 42]
October 22–23
A Hessian force under Colonel Carl von Donop
Count Carl Emil Ulrich von Donop (January 1, 1732Wilhelm Gottlieb Levin von Donop: Des Obermarschalls und Drosten Wilhelm Gottlieb Levin von Donop zu Lüdershofen, Maspe Nachricht von dem Geschlecht der von Donop.' Paderborn 1796p. 21/ref> – O ...
attacked Fort Mercer on October 22 in the Battle of Red Bank
The Battle of Red Bank was a battle fought on October 22, 1777 during the American Revolutionary War in which a British and Hessian force was sent to take Fort Mercer on the left bank (or New Jersey side) of the Delaware River just south of Phil ...
.[Eggenberger, 149] The 1st Rhode Island Regiment under Colonel Christopher Greene
Christopher Greene (May 12, 1737May 14, 1781) was an American legislator and soldier. He lead the spirited defense of Fort Mercer in the 1777 Battle of Red Bank, and for leading the African American 1st Rhode Island Regiment during the American R ...
had arrived at the fort only on October 11 after leaving Peekskill, New York
Peekskill is a city in northwestern Westchester County, New York, United States, from New York City. Established as a village in 1816, it was incorporated as a city in 1940. It lies on a bay along the east side of the Hudson River, across fro ...
on September 29. This was the first black unit in the Continental Army. Colonel Israel Angell
Israel Angell (August 24, 1740 - May 4, 1832) was a Continental Army officer of the American Revolutionary War.
Early life and education
He was born to Oliver and Naomi (Smith) Angell in Providence, Rhode Island.Marquis Who's Who, Inc. ''Who ...
's 2nd Rhode Island Regiment reached Red Bank a week later and Major Thayer was sent with 150 soldiers to help garrison Fort Mifflin. When it became clear that the fort was about to be attacked, Thayer and his men recrossed the river to help in Fort Mercer's defense.[ After Donop summoned the fort to surrender twice and each time received a negative response, he resolved to storm the place. The Rhode Islanders waited until their Hessian adversaries reached the abatis and then opened fire. The result was a one-sided slaughter. Greene's garrison lost 14 killed, 21 wounded, and one captured while inflicting 90 killed, 227 wounded, and 69 captured on their foes. The Hessians lost a high proportion of officers, including Donop who was mortally wounded.
]
The following day saw another stunning disaster for the British. In support of the assault on Fort Mercer, a squadron
Squadron may refer to:
* Squadron (army), a military unit of cavalry, tanks, or equivalent subdivided into troops or tank companies
* Squadron (aviation), a military unit that consists of three or four flights with a total of 12 to 24 aircraft, ...
from Admiral Howe's fleet moved upriver under the command of Captain Francis Reynolds in the ship of the line
A ship of the line was a type of naval warship constructed during the Age of Sail from the 17th century to the mid-19th century. The ship of the line was designed for the naval tactic known as the line of battle, which depended on the two colu ...
(64). Accompanying ''Augusta'' was the sloop
A sloop is a sailboat with a single mast typically having only one headsail in front of the mast and one mainsail aft of (behind) the mast. Such an arrangement is called a fore-and-aft rig, and can be rigged as a Bermuda rig with triangular sa ...
HMS ''Merlin'' (18) under Commander Samuel Reeve and the frigate
A frigate () is a type of warship. In different eras, the roles and capabilities of ships classified as frigates have varied somewhat.
The name frigate in the 17th to early 18th centuries was given to any full-rigged ship built for speed and ...
s HMS ''Roebuck'' (44), Captain Andrew Snape Hamond, HMS ''Pearl'' (32), Captain Wilkinson, and (28), Captain Henry Bellew.[Phillips, ''Augusta''] A force of 200 British Grenadiers waited to make an amphibious assault on Mud Island when the fort's artillery fire was suppressed.
While bombarding Fort Mifflin, ''Augusta'' and ''Merlin'' went aground
Ship grounding or ship stranding is the impact of a ship on seabed or
waterway side. It may be intentional, as in beaching to land crew or cargo, and careening, for maintenance or repair, or unintentional, as in a marine accident. In accidenta ...
. High tide came that evening, but contrary winds prevented sufficient depth for the ships to be freed. On October 23, the American forts concentrated their fire on the two stricken ships. (50) worked its way alongside the stranded ''Augusta'' in a rescue attempt. British accounts claimed that American gunnery did only slight damage but that flaming wads from the ships' guns caused ''Augusta'' to catch fire.[ The Americans asserted that a lucky hit from one of Fort Mifflin's red-hot shot or a ]fire ship
A fire ship or fireship, used in the days of wooden rowed or sailing ships, was a ship filled with combustibles, or gunpowder deliberately set on fire and steered (or, when possible, allowed to drift) into an enemy fleet, in order to destroy sh ...
started the blaze. An American soldier in the fort wrote that the fire started at the stern of ''Augusta'' and that the flames spread rapidly. At mid-day, ''Augusta'' blew up in a tremendous blast that broke windows in Philadelphia. According to Captain Montresor, 60 sailors, a lieutenant, and the ship's chaplain died while struggling in the water. The loud explosion was heard nearly away in Trappe, Pennsylvania
Trappe (Pennsylvania Dutch language, Pennsylvania German: ''Drapp'') is a borough (Pennsylvania), borough in Montgomery County, Pennsylvania, United States. The population was 3,509 at the 2010 census. Augustus Lutheran Church, built in 1743, is ...
. After the destruction of ''Augusta'' the crew of ''Merlin'' set their ship on fire and abandoned ship. At length ''Merlin'' blew up in a less spectacular explosion.
Climax
Beginning on October 26 a nor'easter
A nor'easter (also northeaster; see below), or an East Coast low is a synoptic-scale extratropical cyclone in the western North Atlantic Ocean. The name derives from the direction of the winds that blow from the northeast. The original use o ...
struck the area and the storm lasted for three days, bringing with it high winds and torrential rain. With two feet of water over most of Mud Island and similar conditions on Province and Carpenter's Islands, the mutual cannon fire stopped as both sides tried to find a dry place. By November 1, the Americans had the British army in Philadelphia effectively under blockade. Howe's troops were short of food, rum, clothing, and money. Montresor complained that he lacked adequate artillery and ammunition. The British were compelled to send supplies into Philadelphia via convoys of flatboats. To avoid being sunk by the guns of Fort Mifflin and the Pennsylvania Navy, the boats had to make the attempt in the night and maintain total silence. Hessian Captain Johann von Ewald noted that in order to hold the sailors to their dangerous work, they were made completely drunk.
After a council of war
A council of war is a term in military science that describes a meeting held to decide on a course of action, usually in the midst of a battle. Under normal circumstances, decisions are made by a commanding officer, optionally communicated ...
on October 29, Washington ordered Brigadier General
Brigadier general or Brigade general is a military rank used in many countries. It is the lowest ranking general officer in some countries. The rank is usually above a colonel, and below a major general or divisional general. When appointed ...
James Mitchell Varnum
James Mitchell Varnum (December 17, 1748 – January 9, 1789) was an American legislator, lawyer, generalHeitman, ''Officers of the Continental Army'', 559. in the Continental Army, and a pioneer to the Ohio Country.Wilkins, ''Memoirs of the Rho ...
to assume responsibility for the defense of the Delaware.[ The two Rhode Island regiments of Varnum's brigade were already manning the forts. Soon the last two units of his brigade were committed to the battle. On November 3, Varnum sent the 4th and 8th Connecticut Regiments to garrison Fort Mifflin.
On November 10, Montresor was finally prepared to batter down the fort. By that date he had ready for action two 32-pounder, six 24-pounder, and one 18-pounder cannon plus two 8-inch howitzers, two 8-inch mortars, and one 13-inch mortar. On the 10th, the two sides blazed away at each other at a range of . No casualties were suffered by the Americans but large parts of the palisades on the western side of the island were wrecked. On the 11th, Captain Treat was killed by the concussion of a near miss as he talked with Smith. Later that day as Smith was in the barracks, a cannonball smashed through the chimney and struck him in the left hip. Though covered in bricks from the collapsed chimney and suffering from a dislocated wrist, Smith survived because the round was spent.
The wounded Smith was ferried across to Red Bank, leaving the garrison leaderless. Varnum reported that the troops would welcome a British infantry assault, but that the constant barrage was taking its toll on the men. Fleury wrote to Washington that all the guns were dismounted except two but that the soldiers of the garrison were able to repair the damage to the palisades every night. The only safe place in the fort was a ditch on the east side and Fleury would go there to round up men for work details, lashing out at the laggards with his cane. The next in command after Smith was Lieutenant Colonel Giles Russell of Connecticut, but he declined and asked to be recalled. On November 12 Major Thayer accepted command of the fort.
Sir William Howe began assembling a detachment of light infantry and Foot Guards on November 9, placing them under the command of Lieutenant Colonel ]Sir George Osborn, 4th Baronet
Sir George Osborn, 4th Baronet (10 May 1742 – 29 June 1818) was born into the British aristocracy. He fought in the American Revolutionary War as a British officer. He served in the House of Commons from 1769 to 1784 - before, during, and after ...
. These troops were ready by the 13th and were to be supported by the 27th Foot
The 27th (Inniskilling) Regiment of Foot was an Irish infantry regiment of the British Army, formed in 1689. Under the Childers Reforms it amalgamated with the 108th (Madras Infantry) Regiment of Foot to form the Royal Inniskilling Fusiliers in 18 ...
and 29th Foot. By November 14, the British had planted two additional batteries containing four 32-pounder guns and six 24-pounder guns, which added to the furious daily bombardment. That night Fort Mifflin fired on a supply convoy but missed.
The British brought (20) upriver to attack the fort. ''Vigilant'' was originally the naval transport ''Empress of Russia''. She had been converted in June 1777 into a vessel designed for shore bombardment. For this purpose, the ship carried 14 24-pounder cannon, two 9-pounders, and four 6-pounders. Before the attack, the British strengthened the vessel's sides, added 24 sharpshooters and 50 gunners to the crew, and transferred two extra guns to her starboard side. To maintain the ship's stability, water casks were positioned on the port side. Lieutenant John Henry was the commanding officer. Favored by a high tide, ''Vigilant'' worked its way into the shallow channel between Mud Island and the north bank at 8:00 AM on November 15. Accompanied by the sloop ''Fury'' with three 18-pounder guns, the converted transport hurled a barrage at Fort Mifflin from a distance of . Out in the main channel, (70), ''Isis'', ''Roebuck'', and ''Pearl'' added the weight of their broadsides from a greater distance.
Thayer ordered his 32-pounder cannon to be moved to the place of danger. Before ''Vigilant'' reached her station, the gun crew claimed to have fired 14 shots into her. After the floating battery came to anchor, the fort was subjected to a terrific point blank fire. A single shot killed five American gunners at one cannon. A defender wrote that men were, "split like fish to be broiled". Thayer ordered a distress signal to be hoisted requesting help from Hazelwood, but to do so the fort's flag had to be lowered first. When the British gunners ceased fire and began to cheer in anticipation of victory, Thayer's officers demanded that the flag be immediately raised again. The bombardment resumed and the artillery sergeant detailed to haul the flag was the next casualty, cut in half by a cannonball. That afternoon, a chunk of wood from the smashed barracks struck down artillery Captain James Lee and knocked Fleury unconscious. When Hazelwood's ships tried to attack ''Vigilant'' and ''Fury'', fire from the British naval squadron drove them back. By this time the interior of the fort was furrowed with the tracks of cannonballs and the barracks and blockhouses were wrecked.
Osborn planned to send eight flatboats each with 35 soldiers in the first wave of his assault. Howe declined to give the order for the 400-man storming party to attack, waiting for a high tide and hoping that the garrison would evacuate the fort. That evening at around 11:30 PM, Thayer gave the order to abandon Fort Mifflin. The 300 survivors and what equipment could be salvaged were rowed across to Red Bank. Thayer held back a detail of 40 men. These troops burned down the barracks at midnight and soon joined the others in New Jersey. Thayer was the last one to leave.
Result
At 6:00 AM on the morning of November 16, HMS ''Vigilant'' launched a boat manned by British marines to haul down the American flag, which had been left flying. Two hours later, Osborn's troops landed amid snow flurries and took possession of the ruined fort. They were greeted by a lone American deserter who told them that Thayer's men suffered about 50 killed and 70 to 80 wounded. Historian Mark M. Boatner III estimated total American casualties at 250 killed and wounded[ from a garrison that counted 450 men plus reinforcements. British losses in the last phase of the siege were seven killed and five wounded, nearly all of them were crewman on the ''Vigiliant''.][ The victors were appalled at the damage and at the blood and brains strewn about the fort's interior. While the needy enlisted men were busy looting the corpses for shoes and clothing, a few of the British officers admitted in their letters that the defenders had been brave.
On November 17, Lieutenant General ]Lord Charles Cornwallis
Charles Cornwallis, 1st Marquess Cornwallis, (31 December 1738 – 5 October 1805), styled Viscount Brome between 1753 and 1762 and known as the Earl Cornwallis between 1762 and 1792, was a British Army General officer, general and official ...
crossed the river with 2,000 men to prepare for an assault on Fort Mercer. In the face of this threat, Colonel Greene evacuated Fort Mercer and Cornwallis seized the place unopposed on November 20.[ With the forts gone, Hazelwood set his ships on fire that night to prevent their capture by the British. The Delaware was now open to the Royal Navy and the army of occupation in Philadelphia could be supplied.][ The next action occurred at the Battle of Gloucester on November 25 as Cornwallis withdrew from New Jersey.][McGuire, 221]
See also
Notes
References
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{{DEFAULTSORT:Fort Mifflin, Siege of
Battles involving the United States
Battles involving Great Britain
Battles of the American Revolutionary War in Pennsylvania
Philadelphia in the American Revolution
Conflicts in 1777
1777 in North America
1777 in the United States
1777 in Pennsylvania
Sieges of the American Revolutionary War
Battles of the Philadelphia Campaign