He soon perceived his mistake respecting the force of the British rear, but still determined to engage on that ground, although his judgment disapproved the measure; there being a morass immediately in his rear, which would necessarily impede the reinforcements which might be advancing to his aid, and embarrass his retreat should he be finally overpowered.
This was about ten.

While both armies were preparing for action, General Scott (as stated by General Lee) mistook an oblique march of an American column for a retreat; and, in the apprehension of being abandoned, left his position, and repassed the ravine in his rear.
Being himself of opinion that the ground was unfavourable, Lee did not correct the error he ascribed to Scott, but ordered the whole detachment to regain the heights.

He was closely pressed, and some slight skirmishing ensued without much loss on either side.
As soon as the firing announced the commencement of the action, the rear division of the army advanced rapidly to the support of the front.

As they approached the scene of action, General Washington, who had received no intelligence from Lee giving notice of his retreat, rode forward, and, to his utter astonishment and mortification, met the advanced corps retiring before the enemy, without having made a single effort to maintain its ground.

The troops he first saw neither understood the motives which had governed General Lee, nor his present design; and could give no other information than that, by his orders, they had fled without fighting.
General Washington rode to the rear of the division, where he met General Lee, to whom he spoke in terms of some warmth, implying disapprobation of his conduct.
Orders were immediately given to Colonel Stewart and Lieutenant Colonel Ramsay to form their regiments for the purpose of checking the pursuit; and General Lee was directed to take proper measures with the residue of his force to stop the British column on that ground.