... and take position on the right of our column as it advanced. My corps crossed the Potomac at Williamsport, and General A. P. Hill crossed at Shepherdstown. Our columns were joined together at Hagerstown , and we marched thence into Pennsylvania, reaching Chambersburg on the evening of the 27th. At this point, on the night of the 29th, information was received by which the whole plan of the campaign...