The Second, Fifth, and Sixth Corps were advanced to Frederick, Md., as a support to the First, Third, and Eleventh Corps.

Gregg's cavalry division remained behind to cover the crossing, which was all completed the next day, after which they too marched to Frederick.
On the 25th, Early, leaving his division at Greenwood, went to Chambersburg to consult Ewell, who gave him definite orders to occupy York, break up the Central Railroad, burn the bridge over the Susquehanna at Wrightsville, and afterward rejoin the main body at Carlisle.
It seems strange that Lee should suppose that the Union army would continue inactive all this time, south of Washington, where it was only confronted by Stuart's cavalry, and it is remarkable to find him so totally in the dark with regard to Hooker's movements.

It has been extensively assumed by rebel writers that this ignorance was caused by the injudicious raid made by Stuart, who thought it would be a great benefit to the Confederate cause if he could ride entirely around the Union lines and rejoin Lee's advance at York.
He had made several of these circuits during his military career, and had gained important advantages from them in way of breaking up communications, capturing despatches, etc.

It is thought that he hoped by threatening Hooker's rear to detain him and delay his crossing the river, and thus give time to Lee to capture Harrisburg, and perhaps Philadelphia.

His raid on this occasion was undoubtedly a mistake.