These arrangements being made to cut off supplies from the country, Washington took a strong position at White Marsh, within fourteen miles of Philadelphia.
Meanwhile General Howe was actively preparing to attack Fort Mifflin from the Pennsylvania shore. He erected some batteries at the mouth of the Schuylkill, in order to command Webb's Ferry, which were attacked by Commodore Hazlewood and silenced; but the following night a detachment crossed over Webb's Ferry into Province Island, and constructed a slight work opposite Fort Mifflin, within two musket shots of the blockhouse, from which they were enabled to throw shot and shells into the barracks. When daylight discovered this work three galleys and a floating battery were ordered to attack it and the garrison surrendered. While the boats were bringing off the prisoners, a large column of British troops were seen marching into the fortress, upon which the attack on it was renewed, but without success, and two attempts made by Lieutenant-Colonel Smith to storm it failed. {1}
In a few nights works were completed on the high ground of Province Island, which enfiladed the principal battery of Fort Mifflin, and rendered it necessary to throw up some cover on the platform to protect the men who worked the guns.
The aid expected from the Jersey militia was not received. "Assure yourself," said Lieutenant-Colonel Smith, in a letter pressing earnestly for a reinforcement of Continental troops, "that no dependence is to be put on the militia; whatever men your Excellency determines on sending, no time is to be lost." The garrison of Fort Mifflin was now reduced to 156 effectives, and that of Red Bank did not much exceed 200.
In consequence of these representations Washington ordered Col. Christopher Greene, of Rhode Island, with his regiment, to Red Bank, and Lieut.-Col. John Greene, of Virginia, with about 200 men, to Fort Mifflin.
Immediately after the battle of Brandywine Admiral Howe had sailed for the Delaware, where he expected to arrive in time to meet and cooperate with the army in and about Philadelphia. But the winds were so unfavorable, and the navigation of the Bay of Delaware so difficult, that his van did not get into the river until the 4th of October. The ships of war and transports which followed came up from the 6th to the 8th, and anchored from New Castle to Reddy Island.
The frigates, in advance of the fleet, had not yet succeeded in their endeavors to effect a passage through the lower double row of chevaux-de-frise. Though no longer protected by the fort at Billingsport, they were defended by the water force above, and the work was found more difficult than had been expected. It was not until the middle of October that the impediments were so far removed as to afford a narrow and intricate passage through them. In the meantime the fire from the Pennsylvania shore had not produced all the effect expected from it, and it was perceived that greater exertions would be necessary for the reduction of the works than could safely be made in the present relative situation of the armies. Under this impression, General Howe, soon after the return of the American army to its former camp on the Skippack, withdrew his troops from Germantown into Philadelphia, as preparatory to a combined attack by land and water on Forts Mercer and Mifflin.
After effecting a passage through the works sunk in the river at Billingsport, other difficulties still remained to be encountered by the ships of war. Several rows of chevaux-de-frise had been sunk about half a mile below Mud Island, which were protected by the guns of the forts, as well as by the movable water force. To silence these works, therefore, was a necessary preliminary to the removal of these obstructions in the channel.
On the 21st of October (1777) a detachment of Hessians, amounting to 1,200 men, commanded by Col. Count Donop, crossed the Delaware at Philadelphia with orders to storm Fort Mercer, at Red Bank. The fortifications consisted of extensive outer works, within which was an entrenchment eight or nine feet high, boarded and fraized. Late in the evening of the 22d Count Donop appeared before the fort and attacked it with great intrepidity. It was defended with equal resolution by the brave garrison of Rhode Island Continentals, under command of Col. Christopher Greene. The outer works being too extensive to be manned by the troops in the fort, were used only to gall the assailants while advancing. On their near approach the garrison retired within the inner entrenchment, whence they poured upon the Hessians a heavy and destructive fire. Colonel Donop received a mortal wound, and Lieutenant-Colonel Mengerode, the second in command, fell about the same time. {2}
Lieutenant-Colonel Linsing, the oldest remaining officer, drew off his troops and returned next day to Philadelphia. The loss of the assailants was estimated by the Americans at 400 men. The garrison was reinforced from Fort Mifflin, and aided by the galleys which flanked the Hessians in their advance and retreat. The American loss, in killed and wounded, amounted to only thirty-two men.