Startled by the information, Washington instantly sent off Colonel Theodoric Bland, with a party of horse, to reconnoitre above the forks and ascertain the truth of the report. In the meantime he resolved to cross the ford, attack the division in front of him with his whole force, and rout it before the other could arrive. He gave orders for both wings to co-operate, when, as Sullivan was preparing to cross, Major Spicer of the militia rode up, just from the forks, and assured him there was no enemy in that quarter. Sullivan instantly transmitted the intelligence to Washington, whereupon the movement was suspended until positive information could be obtained. After a time came a man of the neighborhood, Thomas Cheyney by name, spurring in all haste, the mare he rode in foam, and himself out of breath. Dashing up to the commander-in-chief, he informed him that he must instantly move, or he would be surrounded. He had come upon the enemy unawares; had been pursued and fired upon, but the fleetness of his mare had saved him. The main body of the British was coming down on the east side of the stream, and was near at hand. Another despatch from Sullivan corroborated the story. Colonel Bland, whom Washington had sent to reconnoitre above the forks, had seen the enemy two miles in the rear of Sullivan's right, marching down at a rapid rate, while a cloud of dust showed that there were more troops behind them.

In fact, Knyphausen with a small division had engrossed the attention of the Americans by a feigned attack at Chadd's Ford, kept up with great noise and prolonged by skirmishes; while the main body of the army under Cornwallis, led by experienced guides, had made a circuit of seventeen miles, crossed the two forks of the Brandywine, and arrived in the neighborhood of Birmingham meeting-house, two miles to the right of Sullivan. It was a capital stratagem, secretly and successfully conducted.

Finding that Cornwallis had thus gained the rear of the army, Washington sent orders to Sullivan to oppose him with the whole right wing, each brigade attacking as soon as it arrived upon the ground. Wayne, in the meantime, was to keep Knyphausen at bay at the ford, and Greene, with the reserve, to hold himself ready to give aid wherever required. Lafayette, as a volunteer, had hitherto accompanied the commander-in-chief, but now, seeing there was likely to be warm work with the right wing, he obtained permission to join Sullivan, and spurred off with his aide-de-camp to the scene of action.

Sullivan on receiving Washington's orders, advanced with his own, Stephen's and Stirling's divisions, and began to form a line in front of an open piece of wood. The time which had been expended in transmitting intelligence, receiving orders, and marching, had enabled Cornwallis to choose his ground and prepare for action. Still more time was given him from the apprehension of the three generals, upon consultation, of being out-flanked upon the right, and that the gap between Sullivan's and Stephen's divisions was too wide, and should be closed up. Orders were accordingly given for the whole line to move to the right; and while in execution, Cornwallis advanced rapidly with his troops in the finest order, and opened a brisk fire of musketry and artillery. The Americans made an obstinate resistance, but being taken at a disadvantage, the right and left wings were broken and driven into the woods. The centre stood firm for a while, but being exposed to the whole fire of the enemy, gave way at length also. The British, in following up their advantage, got entangled in the wood. Lafayette had thrown himself from his horse and was endeavoring to rally the troops, when he was shot through the leg with a musket ball, and had to be assisted into the saddle by his aide-de-camp.

The Americans rallied on a height to the north of Dilworth, and made a still more spirited resistance than at first, but were again dislodged and obliged to retreat with a heavy loss.

While this was occurring with the right wing, Knyphausen, as soon as he learnt from the heavy firing that Cornwallis was engaged, made a push to force his way across Chadd's Ford in earnest. He was vigorously opposed by Wayne with Proctor's artillery, aided by Maxwell and his infantry. Greene was preparing to second him with the reserve, when he was summoned by Washington to the support of the right wing; which the commander-in-chief had found in imminent peril.

Greene advanced to the relief with such celerity, that it is said, on good authority, his division accomplished the march, or rather run, of five miles in less than fifty minutes. He arrived too late to save the battle, but in time to protect the broken masses of the left wing which he met in full flight. Opening his ranks from time to time for the fugitives and closing them the moment they had passed, he covered their retreat by a sharp and well-directed fire from his field-pieces. His grand stand was made at a place about a mile beyond Dilworth, which in reconnoitring the neighborhood Washington had pointed out to him, as well calculated for a second position, should the army be driven out of the first. Weedon's brigade was drawn up in a narrow defile, flanked on both sides by woods, and perfectly commanding the road; while Greene, with Muhlenberg's brigade, passing to the right took his station on the road. The British came on impetuously, expecting but faint opposition. They met with a desperate resistance and were repeatedly driven back. Weedon's brigade on the left maintained its stand also with great obstinacy, and the check given to the enemy by these two brigades allowed time for the broken troops to retreat. Weedon was at length compelled by superior numbers to seek the protection of the other brigade, which he did in good order, and Greene gradually drew off the whole division in face of the enemy, who, checked by this vigorous resistance, and seeing the day far spent, gave up all further pursuit.

The brave stand made by these brigades had likewise been a great protection to Wayne. He had for a long time withstood the attacks of the enemy at Chadd's Ford, until the approach on the right of some of the enemy's troops, who had been entangled in the woods, showed him that the right wing had been routed. He now gave up the defence of his post and retreated by the Chester road. Knyphausen's troops were too fatigued to pursue him, and the others had been kept back, as we have shown, by Greene's division. So ended the varied conflict of the day.

Lafayette gives an animated picture of the general retreat in which he became entangled. All around him was headlong terror and confusion. Chester road, the common retreat of the broken fragments of the army from every quarter, was crowded with fugitives, with cannon, with baggage cars, all hurrying forward pell-mell, and obstructing each other. At Chester, twelve miles from the field of battle, there was a deep stream with a bridge, over which the fugitives would have to pass. Here Lafayette set a guard to prevent their further flight. The commander-in-chief arriving soon after with Greene and his gallant division, some degree of order was restored, and the whole army took its post behind Chester for the night.