On the 24th, Hooker reported to Halleck, he concluded Ewell to be over the river, and as soon as the force which marched to Shepherdstown yesterday should cross, he should commence moving himself, and if he could do so without observation, send over a corps or two to sever Ewell from the balance of his army. In his testimony before the Committee on the Conduct of the War, General Hooker thus explains his movement:
"As soon as I ascertained that another corps of his (Lee's) was crossing the Potomac, I commenced crossing my own army, and by the time I was over, the whole of the rebel army was on the north side of the Potomac. From Edward's Ferry, where I crossed, I directed General Reynolds to send detachments to seize the passes of South Mountain, Turners and Cramptons, in order to anticipate the enemy passing through them, and confine him to one line of invasion, and directed him to follow those detachments with the first, third, and eleventh corps and take position at Middletown. On the 23d of June, the following instructions were communicated to the 12th corps: 'Hold your command ready to march tomorrow at four A. M. It was to march in the direction of Harper's Ferry, where I was going myself. It had been placed under my command by the orders of the General in Chief, and I directed the twelfth corps to march in that direction for the purpose of being joined by the garrison there, and moving upon Lee's rear upon the Potomac. My object was to destroy his bridges, if he had them; to draw away the guard that was left upon the river, and also to intercept the commerce that Ewell had established in flour, grain, horses and horned cattle, which he was constantly sending to the rear. * * * In connection with this I may state that I was unwilling to send one corps upon Lee's rear, apprehending he might turn upon it and crush it. I had taken the further precaution to send three corps to Middletown to be in position to attack his flank, if it was attempted."
On the evening of the 26th, Hooker proposing to carry out his purpose, telegraphed Halleck, asking, "Is there any reason why Maryland Heights should not be abandoned?" adding that he proposed to visit the place on the next day to satisfy himself on that point. Halleck replied the next morning: "Maryland
