A Hessian colonel stood in the New Jersey countryside, about four miles south of the Delaware River, staring at a half-finished earthen fort defended by four hundred Americans. Behind him, two thousand of Europe’s finest professional soldiers formed up for the assault—grenadiers in tall brass caps and jaeger riflemen who had fought wars before most of these colonists had ever picked up a musket. The colonel had been humiliated at Trenton, had waited nearly a year to erase the stain on his name, and was not leaving New Jersey without a victory. He turned to his officers and pointed toward the fort.
Either it would be called Fort Donop by dusk, he told them, or he would be among the dead. Forty minutes later, he lay in a ditch with his thigh shattered, bleeding to death among the bodies of his men. Nearly four hundred of his elite troops were killed, wounded, or captured across the field. The Americans lost only fourteen men.
In the summer of 1777, British General William Howe loaded a large portion of his army onto transport ships and sailed south from New York to Chesapeake Bay. His objective was Philadelphia, the capital of the fledgling American nation. When Washington tried to stop him at Brandywine Creek on September 11, the Continental Army suffered a severe defeat. The British entered Philadelphia on September 26, and Congress had already fled west to York, Pennsylvania.
On paper, the war seemed close to over. The rebels had lost their capital, and their army was exhausted. Howe had every reason to feel confident. There was only one problem.
Philadelphia sat on the Delaware River, and the only reliable way to supply his army was to send ships up that river from the sea. The overland route from the coast was slow, winding, and completely exposed to American raiding parties that knew the terrain far better than the British. Wagons were ambushed. Militia tore apart supply convoys.
You could not feed an army of several thousand men through a Pennsylvania winter by hauling flour over dirt roads. Howe needed the river open, and for the moment, two American forts were closing it completely. Washington understood this perfectly. If the British could not use the Delaware, their occupation of Philadelphia would become a trap rather than a triumph.
Every week the river stayed closed was another week Howe’s men consumed their stores with no way to replace them. Fort Mifflin sat on a muddy island in the middle of the Delaware on the Pennsylvania side. Fort Mercer stood on high ground at a place called Red Bank on the New Jersey shore, directly across the water. Between the forts, the Americans had planted rows of sharpened wooden obstacles called chevaux de frise into the riverbed—iron-tipped poles designed to tear open the hull of any ship that tried to pass.
A small fleet of Continental Navy vessels and Pennsylvania state navy galleys guarded these gaps. Together, these defenses formed a blockade that no British warship could break. As long as it held, the British army inside Philadelphia was slowly starving. Howe understood the calculation.
Taking the forts and opening the river would turn Philadelphia into a secure British winter stronghold. Failing would make his invasion a trap. So he decided to move. He would attack both forts at once.
The Royal Navy would bombard Fort Mifflin from the water, while a land force would march up and storm Fort Mercer. For that land attack, he turned to the Hessians. These were German soldiers, mostly from the principality of Hesse-Kassel, fighting in America since 1776. Their ruler had hired them out to the British crown for a huge sum, a deal that made him rich and gave King George the professional infantry he needed to fight a war across the Atlantic.
By the time of the Revolution, about thirty thousand German soldiers served in British forces in America, and the Hessians of Hesse-Kassel were the largest and most respected contingent. They had trained rigorously in the Prussian style, mastered the bayonet, and many had fought in the Seven Years’ War in Europe. Americans feared them, and with good reason. At the Battle of Long Island in 1776, Hessian guards had stormed American positions with such ferocity that entire regiments fled.
At White Plains, they had done it again. Stories of those bayonet attacks had circulated among Continental ranks for over a year. These were not volunteer militia who would go home after harvest season. They were professional soldiers who had spent their adult lives fighting.
The man who volunteered to lead the attack on Fort Mercer was Colonel Carl von Donop. Von Donop came from a noble Hessian family and had served as personal adjutant to the ruler himself before crossing the Atlantic. He had fought at Brooklyn Heights, Harlem Heights, and White Plains. By late 1776, he was the de facto commander of British garrisons in southern New Jersey.
He was well connected, highly ambitious, and, by the testimony of those who served alongside him, arrogant. But here is where things become interesting. In December of 1776, von Donop was supposed to be close enough to reinforce the Hessian garrison at Trenton when trouble came. He was not.
When George Washington crossed the Delaware on Christmas night and crushed Colonel Johann Rall’s brigade at Trenton, von Donop’s forces were miles away at Mount Holly. According to his jaeger commander, a man named Johann Ewald, von Donop was spending the holiday with a young widow. Whether the story was entirely true or just a rumor that stuck, the result was the same. Rall’s garrison was destroyed.
Nearly a thousand Hessians were captured, and von Donop, who could have marched to the rescue, did nothing. He was never officially punished, but the stain on his reputation was real. For the next ten months, he carried the weight of Trenton with him like an anchor. So when Howe needed someone to lead the assault on Fort Mercer in October of 1777, von Donop did not hesitate.
He volunteered. This was his chance to prove himself again, to show that Hessian troops could still fight and win, and to settle his personal score with the American rebels once and for all. Howe gave him about two thousand men and sent him across the Delaware. The Americans defending Fort Mercer were in a difficult position too.
Colonel Christopher Greene of Warwick, Rhode Island, had endured more trials than most Continental officers by this point. In 1775, he volunteered for Benedict Arnold’s famous march through the Maine wilderness to attack Quebec, an arduous journey in which men nearly starved and froze in the northern forests. Greene took part in the assault on Quebec City on New Year’s Eve and was captured when the attack failed. He spent the next year and eight months as a British prisoner of war before being exchanged in August of 1777.
When he returned home, he learned he had been promoted to colonel of the First Rhode Island Regiment while locked in a British jail. He barely had time to recover before Washington needed him again. In early October, Washington ordered Greene to take the First Rhode Island Regiment, along with the Second Rhode Island Regiment under Colonel Israel Angell, to Fort Mercer at Red Bank. Their mission was simple on paper.
Hold the fort. Keep the river closed. Buy time for the Continental Army. The problem was numbers.
Greene arrived at Red Bank in mid-October with about four hundred men from the two regiments. Some sources put the number slightly higher, perhaps closer to five hundred if New Jersey militia and a small company of Continental artillery were added, but the core fighting force was the two Rhode Island regiments, and many of the men were exhausted after months of campaigning. The fort they were supposed to defend had been designed for a much larger garrison. It was a rectangular earthen rampart stretching about three hundred and twenty yards, surrounded by a ditch and a wall of jagged logs called an abatis, with fourteen cannons aimed mostly toward the river.
The Polish engineer Tadeusz Kosciuszko had helped design the original plan, but with only four hundred men to defend it, the place was simply too big. Greene could spread his troops along the entire perimeter, making them few everywhere. Or he could concentrate them and leave whole sections empty. Neither option was good.
And here, a twenty-four-year-old French engineer changed everything. Thomas Antoine de Mauduit du Plessis arrived at Fort Mercer before the Hessian attack, took one look at the situation, and immediately saw the solution. The fort was too large, so he decided to make it smaller. He ordered the construction of a new interior wall cutting off the northern section of the fort, effectively splitting it in two.
The southern section, roughly pentagonal in shape, became the actual fort. Greene packed his four hundred men into this tighter space, where they could actually cover every wall with concentrated fire. The northern section, the part behind the new interior wall, was simply evacuated. But here is what made this move a masterpiece.
The new interior wall was not visible from outside the fort. From the perspective of the approaching Hessians, the outer walls of the abandoned northern section looked just as fortified as the rest of the fort. The attacking force would storm those outer fortifications, climb the ditch, cross the abatis, and pour into the fort thinking they had breached the defenses, only to slam into a second wall they never knew existed. The abandoned section became a killing ground, a dead zone surrounded on three sides by American muskets and cannons loaded with grapeshot.
Du Plessis also strengthened the inner fort’s walls, fitted them with firing platforms, and positioned all fourteen cannons so they could rake the abandoned outer section with devastating enfilading fire. By the time he finished, four hundred men could defend that fort as effectively as a garrison three times larger. It was a simple idea, and it proved to be one of the most effective defensive tricks of the entire war. On October 21, the Hessian column under von Donop crossed the Delaware and landed at Cooper’s Ferry in what is now Camden, New Jersey.
They camped overnight about four miles from Fort Mercer. Inside the fort, Greene and his men knew the Hessians were coming. Local farmers had reported the column’s movements, and the Americans had spent their final days preparing for this kind of attack. The men slept with loaded muskets and dry powder.
At three in the morning on October 22, the Hessians struck camp and resumed their march. By late afternoon, two thousand Hessians reached Red Bank and began forming up for the assault in the fading autumn light. Von Donop organized his force into three columns. He anchored the flanks of his army on the Delaware River and arranged his battalions in an arc around the landward side of the fort.
Each assault unit carried bundles of sticks called fascines, meant to be thrown into the ditch for the soldiers to cross. What they did not carry were axes and saws to cut through the thorny abatis. That turned out to be a fatal mistake. At four in the afternoon, von Donop sent an officer and a drummer under a white flag with a message to Colonel Greene.
The message was blunt. The King of England ordered his rebellious subjects to lay down their arms. If they refused and chose to fight, there would be no mercy. Greene’s response was equally blunt.
We ask for no mercy, nor will we give any. Von Donop got the answer he wanted. He turned to his men and gave the order to attack. The Hessian columns advanced at a rapid pace, trying to cross the open ground as quickly as possible while American artillery and the guns of three American warships in the river pounded them from flank and rear.
The bombardment was fierce, but the Hessians were professionals and kept coming. A column led by Lieutenant Colonel von Minigerode charged toward the northern front of the fort. The other two columns, under Colonels von Mirbach and von Lensing, attacked the eastern and southern walls. Minigerode’s men hit the outer fortifications first.
They pushed through a thin American skirmish line, climbed the ditch, fought their way through the abatis, and poured into the fort. For a moment, they thought they had won. The northern section of Fort Mercer was empty. They were inside the walls.
Then they saw it—a second wall, higher and more heavily fortified than the first, with American muskets and cannons protruding from every opening. They had walked directly into du Plessis’s trap. The Americans opened fire at point-blank range. Musket balls tore into the packed Hessian ranks.
The cannons, loaded with small lead balls, unleashed a hail of iron fragments that shredded bodies at close range. The Rhode Islanders had been waiting for this moment, and they did not waste it. Some lit grenades and hurled them over the wall into the crowds of Hessians trapped below, where the explosions sent shrapnel and smoke in every direction. On the other two sides of the fort, Mirbach’s and Lensing’s battalions faced an even worse situation.
Those sections of the wall were fully manned by American defenders, and the Hessians never came close to breaching them. The wooden abatis slowed their advance significantly. These were not small branches. They were whole trees, felled and sharpened, with their branches cut into pointed tips and facing outward toward the attackers, forming an entangled barrier that was nearly impossible to penetrate under fire.
Without axes or saws, the Hessians had no way to cut through. Men tried to climb, tried to squeeze between the stakes, while the Americans on the wall above kept firing. Soldiers spread out in a line to try to find gaps in the obstacles, which only made them easier targets, because a spread-out line moves slowly and presents more bodies to aim at. American musket fire mowed them down as they floundered in the ditch, tangled in the jagged wood, unable to advance and unwilling to retreat.
The American warships in the Delaware rained cannonballs and grapeshot on the Hessian flanks and rear the entire time. The Hessians had placed a battalion of grenadiers to try to suppress the ships, but a land unit could do little against vessels maneuvering in the water. The crossfire was devastating. Von Donop himself fell somewhere near the ditch on the southern side of the fort.
A burst of grapeshot or shrapnel shattered his thigh, and he collapsed among the dead and dying. With their commander wounded and the attack failing on all fronts, the Hessian officers still standing tried to rally their men for another push. They managed two more assaults, then a third, but none advanced farther than the first. The fire coming from behind those walls was too heavy.
After about forty minutes of fighting, the surviving Hessians withdrew. They left their dead and wounded scattered across the ditches and tangled in the abatis around the fort. The battle was over. The scene outside Fort Mercer after the fighting stopped was horrific.
Hessian corpses lay in heaps in the ditches and among the sharpened stakes. The official Hessian report listed eighty-two killed, two hundred and twenty-eight wounded, and about sixty missing or captured, though some accounts put the total near four hundred. Inside the fort, American losses were astonishingly light—fourteen killed and twenty-three wounded. That ratio is almost unbelievable, and it reflects just how effective du Plessis’s fortification design really was.
After the firing stopped, du Plessis himself went out beyond the walls to survey the damage and repair some of the abatis that had been torn during the assault. As he walked among the bodies, he heard a voice calling from the ditch. Whoever you are, get me out of here. It was Colonel von Donop, lying among his dead men with his thigh shattered, unable to move.
Du Plessis realized he was speaking to the enemy commander. He ordered the wounded colonel brought inside the fort, and later von Donop was moved to the house of a woman named Ann Whitall, which the Americans were using as a field hospital. Von Donop was placed alongside other wounded soldiers, American and Hessian alike. When Greene came to see the dying colonel, things could easily have gone badly.
The surrender demand von Donop himself had delivered had threatened no mercy. His men had been ordered to show no compassion. The Americans had every reason to treat him harshly. They did not.
Von Donop reportedly looked at his captors and said he was in their hands and they could take revenge on him. And when he realized du Plessis was a French officer, he switched to French and said he was content to die at the hands of honor itself. Von Donop lingered for three days. On October 25, he died in the house of a local man named Joseph Low.
According to multiple sources, his last words were that this was an early end to a promising career, and that he died a victim of his own ambition and the avarice of his prince. He was buried with military honors at Red Bank on the banks of the Delaware, where the river has likely swept away his grave over the centuries. The disaster was not over for the British. The day after the Hessian assault, October 23, a squadron of British warships tried to force their way past the Americans on the river.
The fleet was led by HMS Augusta, a ship of the line carrying sixty-four guns and one of the largest vessels in the Royal Navy. Alongside her were HMS Roebuck, HMS Pearl, HMS Liverpool, and the small sloop HMS Merlin. Their mission was to break through the underwater obstacles, suppress the forts with naval gunfire, and finally open the river. It went wrong almost immediately.
Navigating the narrow channels between the sunken obstacles and shifting sandbars was hazardous even in calm conditions. Under fire, doing it precisely was nearly impossible. Both the Augusta and the smaller Merlin ran hard aground on a sandbar while trying to maneuver into position. Stuck there, unable to turn or retreat, they became easy targets for the American guns firing from Fort Mifflin and from the Continental warships surrounding them in the water.
The Americans poured every bit of firepower they had into the two stranded vessels. Shot after shot slammed into the Augusta’s hull. At some point, a fire broke out aboard her. Whether the fire was caused by a lucky American hit or by the overheating of the Augusta’s own guns during the engagement remains a matter of debate.
But once the flames took hold, they could not be extinguished. The fire worked its way below deck and reached the ship’s powder magazine. The explosion was enormous, one of the largest ever witnessed in the region. Philadelphia residents, miles away, heard the blast and felt its shockwave.
More than sixty British sailors died in the explosion. The Augusta sank as the largest British warship lost in both the Revolutionary War and the War of 1812. Merlin’s crew set fire to their ship and abandoned her to prevent her from falling into American hands. Within about twenty-four hours, the British had lost nearly four hundred Hessian soldiers and two warships, and had not advanced one inch toward opening the Delaware.
The victory at Red Bank did not guarantee Fort Mercer’s survival forever. General Howe was furious at the failure and immediately began planning a larger, more organized attack on the river forts. From late October through November, British artillery batteries on the Pennsylvania shore bombarded Fort Mifflin so heavily that the small island fort was practically reduced to rubble. By November 15, the garrison at Fort Mifflin was forced to evacuate.
Without the partner fort on the other side of the river, Fort Mercer’s continued existence became impossible. Greene’s men abandoned it on November 20, and the British finally opened their supply line before winter fully set in. But here is the significance of Red Bank in the larger picture. Those extra weeks the forts held out were not worthless.
Every day the British could not supply Philadelphia by river was another day of pressure on Howe’s army—another day of dwindling rations, of frustrated officers and troops wondering why the world’s most powerful navy could not get past two small forts. And every one of those days gave Washington’s exhausted Continental Army a chance to regroup, reorganize, and prepare for what was coming, which turned out to be the long, brutal winter at Valley Forge. The army that marched into Valley Forge in December 1777 was exhausted and undersupplied, but it was not broken. Red Bank was part of the reason why.
The victory gave the American side something it desperately needed at that stage of the war—proof that they could hold their ground and fight against professional European soldiers on a prepared battlefield and win. Not just survive a skirmish, not retreat in good order and call it a draw, but destroy an attacking force outnumbering them five to one and force the survivors to limp back to their lines. Christopher Greene, the man who held the fort that day, went on to make more history. After the losses at Red Bank and the rest of the 1777 campaign reduced the Rhode Island regiments’ numbers, General James Varnum petitioned Washington to allow enslaved men to enlist, and Washington agreed.
Greene returned to Rhode Island and recruited formerly enslaved Black men into the First Rhode Island Regiment, creating one of the first African American units in American military history. That regiment fought with distinction at the Battle of Rhode Island in 1778 and later served at Yorktown when Cornwallis surrendered in 1781. Greene himself did not live to see the war’s end. In May of 1781, he was attacked and killed by a Loyalist raiding party along the Croton River in New York.
Some historians believe he was specifically targeted because he was leading Black troops. Von Donop went to Red Bank seeking glory and found his grave. Greene went there with four hundred men, a French engineer, and a simple plan, and achieved one of the most remarkable defensive victories of the Revolution.
The battle lasted forty minutes, but the story behind it—the disgraced Hessian colonel, the defiant Rhode Islander, the invisible wall inside the fort—is the kind of story that deserves to be remembered far more than it is now.