General Greene was selected for this expedition. A hope was entertained that he would be able not only to protect Fort Mercer, but to obtain some decisive advantage over Lord Cornwallis, as the situation of the fort, which his lordship could not invest without placing himself between Timber and Manto creeks, would expose the assailants to great peril from a respectable force in their rear. But, before Greene could cross the Delaware, Cornwallis approached with an army rendered more powerful than had been expected by the junction of the reinforcement from New York, and Fort Mercer was evacuated. A few of the smaller galleys escaped up the river, and the others were burnt by their crews.
Washington still hoped to recover much of what had been lost. A victory would restore the Jersey shore, and this object was deemed so important that General Greene's instructions indicated the expectation that he would be in a condition to fight Cornwallis.
Greene feared the reproach of avoiding an action less than the just censure of sacrificing the real interests of his country by engaging the enemy on disadvantageous terms. The numbers of the British exceeded his, even counting his militia as regulars, and he determined to wait for Glover's brigade, which was marching from the north. Before its arrival, Cornwallis took post on Gloucester point, a point of land making deep into the Delaware, which was entirely under cover of the guns of the ships, from which place he was embarking his baggage and the provisions he had collected for Philadelphia.
Believing that Cornwallis would immediately follow the magazines he had collected, and that the purpose of Howe was, with his united forces, to attack the American army while divided, General Washington ordered Greene to re-cross the Delaware and join the army.
Thus, after one continued struggle of more than six weeks, in which the Continental troops displayed great military virtues, the army in Philadelphia secured itself in the possession of that city by opening a free communication with the fleet.
While Lord Cornwallis was in Jersey, and General Greene on the Delaware above him, the reinforcements from the north being received, an attack on Philadelphia was strongly pressed by several officers high in rank, and was, in some measure, urged by that torrent of public opinion, which, if not resisted by a very firm mind, overwhelms the judgment, and by controlling measures not well comprehended may frequently produce, especially in military transactions, the most disastrous effects. The officers who advised this measure were Lord Stirling, Generals Wayne, Scott, and Woodford. The considerations urged upon Washington in its support were: That the army was now in greater force than he could expect it to be at any future time; that being joined by the troops who had conquered Burgoyne, his own reputation, the reputation of his army, the opinion of Congress and of the nation required some decisive blow on his part; and that the rapid depreciation of the paper currency, by which the resources for carrying on the war were dried up, rendered indispensable some grand effort to bring it to a speedy termination.
Washington reconnoitered the enemy's lines with great care and took into serious consideration the plan of attack proposed. The plan proposed was that General Greene should embark 2,000 men at Dunks' ferry, and descending the Delaware in the night land in the town just before day, attack the enemy in the rear, and take possession of the bridge over the Schuylkill; that a strong corps should march down on the west side of that river, occupy the heights enfilading the works of the enemy, and open a brisk cannonade upon them, while a detachment from it should march down to the bridge and attack in front at the same instant that the party descending the river should commence its assault on the rear.
Not only the Commander-in-Chief, but some of his best officers—those who could not be impelled by the clamors of the ill-informed to ruin the public interests—were opposed to this mad enterprise. The two armies, they said, were now nearly equal in point of numbers, and the detachment under Lord Cornwallis could not be supposed to have so weakened Sir William Howe as to compensate for the advantages of his position. His right was covered by the Delaware, his left by the Schuylkill, his rear by the junction of those two rivers, as well as by the city of Philadelphia, and his front by a line of redoubts extending from river to river and connected by an abatis and by circular works. It would be indispensably necessary to carry all these redoubts, since to leave a part of them to play on the rear of the columns while engaged in front with the enemy in Philadelphia would be extremely hazardous. Supposing the redoubts carried and the British army driven into the town, yet all military men were agreed on the great peril of storming a town. The streets would be defended by an artillery greatly superior to that of the Americans, which would attack in front, while the brick houses would be lined with musketeers, whose fire must thin the ranks of the assailants.
A part of the plan, on the successful execution of which the whole depended, was that the British rear should be surprised by the corps descending the Delaware. This would require the concurrence of too many favorable circumstances to be calculated on with any confidence. As the position of General Greene was known, it could not be supposed that Sir William Howe would be inattentive to him. It was probable that not even his embarkation would be made unnoticed, but it was presuming a degree of negligence which ought not to be assumed to suppose that he could descend the river to Philadelphia undiscovered. So soon as his movement should be observed, the whole plan would be comprehended, since it would never be conjectured that Greene was to attack singly.
If the attack in front should fail, which was not even improbable, the total loss of the 2,000 men in the rear must follow, and General Howe would maintain his superiority through the winter.