The movement to the rear was favored by the darkness and a thick fog, which settled over the valleys, but did not extend to the high ground.

As Benham and Sedgwick, who were classmates at West Point, walked on the slope of the hill where the men were lying--the crest above being held by thirty-four guns on the opposite side of the river--Benham cautioned Sedgwick not to recross under any circumstances without his entire command, nor without Hooker's express sanction, advice which Sedgwick was wise enough to follow.
The enemy did not assail the new position or attempt to interfere with the crossing which soon after took place.

When it was nearly concluded, an order came from Hooker countermanding it, but it was then too late to return.
Howe thinks Sedgwick should not have crossed, as the last attack on the left, which was the vital point, had been repulsed.

This may be so, in the light of after-consideration, but it was very doubtful at the time, and as Sedgwick had lost a fraction under five thousand men in these operations, and was acting under the false information that additional forces had come up from Richmond, he felt that he had fully borne his share of the burden, and that it was better to place his corps beyond the risk of capture, than to run the chances of renewing the battle.

It would, undoubtedly, have been of immense advantage to the cause if he could have continued to hold Taylor's Hill, which dominated the country round, and was the key of the battle-field; for in that case Hooker might have withdrawn from Lee's front and joined Sedgwick, which would have been attaining the object for which our main army left Falmouth, and made the turning movement.