Pleasonton spent the night in fortifying this hill, and placed forty guns in position there; but it was of no avail, for it was outside of the new line Sickles was directed to occupy at daylight, and Hooker was not aware of its importance.

A request was sent to the latter to obtain his consent to hold it, but he was asleep, and the staff- officer in charge, who had had no experience whatever in military matters, positively refused to awaken him until daylight, and then it was too late, for that was the time set for the troops to fall back to the new line.
At 9 P.M., Hooker sent an order to Sedgwick, who was supposed to be at Falmouth and to have 26,000 men, to throw bridges over, cross, drive away Early's 9,000, who held the heights of Fredericksburg, and then to come forward on the Plank Road, and be ready at daylight on the 3d to take Lee's force in reverse, while Hooker attacked it in front.
This order was given under the impression that Sedgwick had not crossed with his main body, but only with Howe's division, whereas he was at the bridge heads, three miles below Fredericksburg, on the south side of the river.

Hooker probably forgot that he had ordered a demonstration to be made against the Bowling Green road on the 1st, and that Sedgwick went over to make it..