This half hour's delay, however, of nearly one-half of the army, disconcerted the action. The divisions and brigades thus separated from each other by the skirmishing attack upon Chew's House, could not be re-united. The fog and smoke rendered all objects indistinct at thirty yards' distance; the different parts of the army knew nothing of the position or movements of each other, and the commander-in-chief could take no view nor gain any information of the situation of the whole. The original plan of attack was only effectively carried into operation in the centre. Still the action, though disconnected, irregular and partial, was animated in various quarters. Sullivan, being reinforced by Nash's North Carolina troops and Conway's brigade, pushed on a mile beyond Chew's House, where the left wing of the enemy gave way before him.
Greene and Stephen, with their divisions, having had to make a circuit, were late in coming into action, and became separated from each other, part of Stephen's division being arrested by a heavy fire from Chew's House and pausing to return it. Greene, however, with his division, pressed rapidly forward, drove an advance regiment of light-infantry before him, took a number of prisoners, and made his way quite to the market-house in the centre of the village, where he encountered the right wing of the British drawn up to receive him. The impetuosity of his attack had an evident effect upon the enemy, who began to waver. Forman and Smallwood, with the Jersey and Maryland militia, were just showing themselves on the right flank of the enemy, and our troops seemed on the point of carrying the whole encampment. At this moment a singular panic seized our army. Various causes are assigned for it. Sullivan alleges that his troops had expended all their cartridges, and were alarmed by seeing the enemy gathering on their left, and by the cry of a light-horseman, that the enemy were getting round them. Wayne's division, which had pushed the enemy nearly three miles, was alarmed by the approach of a large body of American troops on its left flank, which it mistook for foes, and fell back in defiance of every effort of its officers to rally it. In its retreat it came upon Stephen's division and threw it into a panic, being, in its turn, mistaken for the enemy; thus all fell into confusion, and our army fled from their own victory.
In the meantime the enemy, having recovered from the first effects of the surprise, advanced in their turn. General Grey brought up the left wing, and pressed upon the American troops as they receded. Lord Cornwallis, with a squadron of light-horse from Philadelphia, arrived just in time to join in the pursuit. The retreat of the Americans was attended with less loss than might have been expected, and they carried off all their cannon and wounded. The retreat continued through the day to Perkiomen Creek, a distance of twenty miles.
The loss of the enemy in this action is stated by them to be seventy-one killed, four hundred and fifteen wounded, and fourteen missing: among the killed was Brigadier-general Agnew. The American loss was one hundred and fifty killed, five hundred and twenty-one wounded, and about four hundred taken prisoners. Among the killed was General Nash of North Carolina. Among the prisoners was Colonel Mathews of Virginia.
The sudden retreat of the army gave Washington surprise, chagrin and mortification. "Every account," said he subsequently, in a letter to the President of Congress, "confirms the opinion I at first entertained, that our troops retreated at the instant when victory was declaring herself in our favor. The tumult, disorder, and even despair which it seems had taken place in the British army, were scarcely to be paralleled; and it is said, so strongly did the ideas of a retreat prevail, that Chester was fixed on for their rendezvous. I can discover no other cause for not improving this happy opportunity, than the extreme haziness of the weather."
The plan of attack was too widely extended for strict concert, and too complicated for precise co-operation, as it had to be conducted in the night, and with a large proportion of undisciplined militia.
But although the Americans were balked of the victory, which seemed within their grasp, the impression made by the audacity of this attempt upon Germantown was greater we are told than that caused by any single incident of the war after Lexington and Bunker's Hill.
Washington remained a few days at Perkiomen Creek, to give his army time to rest and recover from the disorder incident to a retreat. Having been reinforced by the arrival of twelve hundred Rhode Island troops from Peekskill, under General Varnum, and nearly a thousand Virginia, Maryland and Pennsylvania troops, he gradually drew nearer to Philadelphia, and took a strong position at White Marsh, within fourteen miles of that city. By a resolution of Congress, all persons taken within thirty miles of any place occupied by British troops, in the act of conveying supplies to them, were subjected to martial law. Acting under the resolution, Washington detached large bodies of militia to scour the roads above the city, and between the Schuylkill and Chester, to intercept all supplies going to the enemy.
On the forts and obstructions in the river, Washington mainly counted to complete the harassment of Philadelphia. These defences had been materially impaired. The works at Billingsport had been attacked and destroyed, and some of the enemy's ships had forced their way through the chevaux-de-frise placed there. The American frigate Delaware, stationed in the river between the upper forts and Philadelphia, had run aground before a British battery and been captured.
It was now the great object of the Howes to reduce and destroy, and of Washington to defend and maintain the remaining forts and obstructions. Fort Mifflin, which we have already mentioned, was erected on a low, green, reedy island in the Delaware, a few miles below Philadelphia, and below the mouth of the Schuylkill. It consisted of a strong redoubt with extensive outworks and batteries. There was but a narrow channel between the island and the Pennsylvania shore. The main channel, practicable for ships, was on the other side. In this were sunk strong chevaux-de-frise, difficult either to be weighed or cut through, and dangerous to any ships that might run against them; subjected as they would be to the batteries of Fort Mifflin on one side, and on the other to those of Fort Mercer, a strong work at Red Bank on the Jersey shore.