...e presence of the enemy in Crampton Gap. He retained his position until the 14th, when, finding that he was not to be attacked, he gradually withdrew his command toward the Potomac, then crossed at Harpers Ferry and marched by way of Shepardstown. His progress was slow, and he did not reach the battle-field at Sharpsburg until some time after the engagement of the 17th began. At this time the letter f...