...l-supplied trains had passed my rear, I was ordered to withdraw from the Blue Ridge, pass over to the west of the Shenandoah and follow the movements of the other troops, only to cross the Potomac at Williamsport . I ordered General Stuart, whom I considered under my command, to occupy the gaps with a part of his cavalry and to follow with his main force on my right, to cross the Potomac at Shepherdstown, an...