At the
Battle of Germantown on 4 October 1777, the American offensive stalled when Lieutenant Colonel Thomas Musgrave and 120 British soldiers of the
40th Foot stoutly defended the
Chew House. After artillery and infantry assaults failed, du Plessis and other officers attempted to set the house on fire. To fellow aide
John Laurens, du Plessis suggested the idea of fetching hay from the nearby barn and using it to ignite the structure. Using the kitchen outbuilding as cover, du Plessis reached a ground-floor window to the left of the servant's entrance. He smashed it and tried to climb in. Perched on the window sill, he found himself face to face with a pistol-wielding British officer who demanded his surrender. At that moment, a British soldier burst into the room and fired at du Plessis but hit the officer by mistake. After this close call, the Frenchman decided to retreat. With numerous American soldiers looking on, he refused to run for it. He later claimed that he retired at a walk, which he managed to do without being shot, though Laurens was slightly wounded in the shoulder. Two of
Major General John Sullivan's aides, Captains John White and Edward Sherburne were killed while unsuccessfully trying to carry out this dangerous mission. Later that month,
George Washington sent du Plessis to
Fort Mercer to take command of the garrison's artillery and also to oversee its defenses. When he reported to Colonel
Christopher Greene on 11 October, he found a sprawling fortress that was long and wide. The works were far too extensive for the 250 defenders and 14 cannons. Du Plessis immediately constructed a new wall that bisected the old works, effectively abandoning a large part of the fort in order to concentrate the defenses in a smaller area. Since fruit trees made excellent
abatis, James Whitall's nearby orchard was entirely cut down for the purpose. For his part, Greene ordered every available man to help the French engineer improve the fort's defenses.
Sir William Howe ordered an expedition under Colonel
Carl von Donop to capture Fort Mercer. Donop took 2,000 infantry, including
Ludwig von Wurmb's Hessian and Ansbach Jäger Corps, the
Mirbach Hessian Infantry Regiment, and the
Lengerke,
Linsing, and
Minningerode Hessian grenadier battalions. These were accompanied by 10 Hessian 3-pound battalion cannons and Captain-lieutenant Francis Downman's two 5.5-inch howitzers of the British Royal Artillery. Donop's soldiers crossed the
Delaware River into New Jersey on the morning of 21 October 1777 and camped at
Haddonfield that night. Around noon on 22 October, the expedition approached the fort and initiated the
Battle of Red Bank. That morning, Colonel
Israel Angell's
2nd Rhode Island Regiment was ferried across the Delaware from
Fort Mifflin to assist Greene's
1st Rhode Island Regiment. Altogether, Greene commanded about 500 defenders. Soon afterward, a Hessian drummer beat a parley and Major
Charles Stuart, accompanied by a Hessian officer, came forward to demand the fort's surrender. Greene sent Lieutenant Colonel
Jeremiah Olney to meet the British major. Though Stuart threatened in a loud voice that no quarter would be given to the defenders, Olney refused. Du Plessis later related to
François-Jean de Chastellux that Stuart's overbearing tone inspired the defenders to greater resistance. Donop waited for two hours and sent a second surrender demand to the fort. When it was refused again, he prepared to attack. Donop ordered the
Minningerode Grenadiers to attack the right or east side of the fort, the
Mirbach Musketeers to assault the center, and the
Linsing Grenadiers to charge the left or west side. He held the
Lengerke Grenadiers in reserve. Jäger sharpshooters found positions where they could pick off the defenders. At 4:30 PM, the Hessian infantry advanced after a brief artillery bombardment. Donop led the
Minningerode column which rushed into the abandoned eastern section of the fort. Though they were sprayed by grapeshot from American gunboats, the grenadiers forced their way into the abatis. At that moment, the defenders opened fire from point-blank range and simply mowed down the Germans. Despite the efforts of the officers to urge the men on, all three attacking columns were stopped with horrific losses and forced to retreat. The Hessians lost eight officers, seven
non-coms, and 75 privates killed. There were 15 officers, 24 non-coms, and 188 privates wounded. One non-com and 68 privates were missing, making a total of 382 casualties. The Americans lost 14 killed, 21 wounded, and one captured. De Plessis sortied from the fort with a few men in the evening and captured 20 Hessians. That night, amid the horrible groans of the wounded Hessians, du Plessis heard a voice in English pleading for help. He went with a few men, found Donop with a shattered left thigh bone, and brought him into the works. Though some Americans taunted the wounded Hessian with his "no quarter" message, du Plessis managed to calm the men down and get medical treatment for his adversary. Donop died of his wound a week later. Though Stuart was in the forefront of the attack, he survived unscathed. ==Valley Forge and Monmouth==