About noon Washington heard of Cornwallis's march. He promptly determined to cross the stream and engage Knyphausen, while Cornwallis was too far distant to reinforce him or threaten the American right. Wayne, Greene, and Sullivan's divisions were ordered to advance. Greene had gained the west bank when word was received from Sullivan that a Major Spear had assured him that there must be some mistake. He had that morning passed over the road Cornwallis was said to be on, and had seen nothing of him. Fearing that Cornwallis's march was only a feint, and that he had returned and rejoined Knyphausen, Washington ordered Greene back and sent scouts out for additional information. By two o'clock it was obtained. Cornwallis was discovered on the road to Dilworth, and would soon be in the rear of the Americans. Stirling and Stephen were deployed on the hill southwest of Birmingham Meeting-House, and Sullivan's division was ordered to join them. Before it could reach its position Cornwallis began the attack. As he attempted to turn the American right, Sullivan endeavored to move his three divisions to the east. His own division had been formed in line half a mile from those of Stirling and Stephen, and in closing the gap it fell into confusion and was routed. With the divisions of Stirling and Stephen, Sullivan made every effort to hold the position; but he was outnumbered, his left flank was uncovered, and his entire command was finally driven in confusion from the field. Sullivan, Stirling, and Conway had encouraged their men with exhibitions of personal bravery, and Lafayette, who acted as a volunteer, was wounded while endeavoring to rally some fugitives. When Washington heard the firing in the direction of Birmingham he rode thither with the utmost speed. Meeting the fugitives, he ordered Greene to support the right wing. The order was executed with wonderful promptness. Greene, throwing Weedon's brigade on the flank of the enemy and Muhlenberg's in their front, checked the pursuit. But the Americans were obliged to fall back until they came to a narrow defile, flanked on both sides by woods, from which the British could not drive them, and night ended the conflict. When Knyphausen learned that Cornwallis was engaged he pushed across the stream at Chad's Ford, but Wayne, Maxwell, and Proctor held him in check until they found that the right wing had been defeated, when they retired in good order, fighting as they fell back towards Chester. There at night the defeated army gathered, and Washington reported to Congress that, notwithstanding the misfortunes of the day, his troops were in good spirits.