Impelled by public opinion he kept on his way up the Cumberland Valley.

Hooker being very desirous of keeping the invasion west of the Blue Ridge, asked Heintzelman to co-operate with him by sending the 2,000 men which seemed to be of no service at Poolesville to the passes of South Mountain, which is an extension of the same range; but Heintzelman said those passes were outside of his jurisdiction, and the men were needed in Poolesville.

Hooker replied somewhat angrily that he would try and do without the men.

The two generals had quarreled, and there was not the best feeling between them.
All of Ewell's corps were across the river on the 22d, and Jenkins' cavalry pushed on to Chambersburg.

He was ordered to remain there until reinforced, but failed to do so, as Union troops were approaching from the direction of Carlisle.
Longstreet and Hill were left behind to prevent Hooker from striking the rear of this long column.