- McClellan crosses the Potomac, and advances to Frederick -- address to Maryland -- McClellan follows to Frederick -- Lee's plans discovered -- he is intent on the capture of Harper's Ferry -- McClellan fights and beats his rear-guard at Turner's Gap -- Franklin drives Howell Cobb out of Crampton's Gap -- miles surrenders Harper's Ferry, with 12,000 men, to Stonewall Jackson -- McClellan follows Lee to the Antietam -- battle of Antietam or Sharpsburg -- losses -- Lee retreats across the Potomac -- Porter follows -- McClellan hesitates to pursue -- J. E. B. Stuart raids around his army -- McClellan moves down to the Rappahannock -- is relieved by Burnside.
Gen. Mcclellan had already1 been verbally charged with the command of the defenses of Washington; and was, upon fuller advices of Pope's disasters, invested2 by the President and Gen. Halleck with the entire control, not only of those fortifications, but of “all the troops for the defense of the capital,” in obedience to the imperious demand of a large majority of the surviving officers and soldiers. Pope's original army had in great part been demolished; while that brought from the Peninsula by McClellan had been taught to attribute the general ill-fortune not to the tardiness and heartlessness wherewith Pope had been reenforced and supported by their leaders, but to his own incapacity, presumption, and folly. McClellan at once ordered a concentration of his forces within the defenses of Washington; where they were soon prepared to resist the enemy, but whither Lee had no idea of following them. Having been joined3 by D. H. Hill's fresh division, from Richmond, he sent that division at once in the van of his army to Leesburg; thence crossing, the Potomac and moving on Frederick. Jackson followed with a heavy corps, consisting of A. P. Hill's, Ewell's, and his own divisions) embracing 14 brigades, crossing4 at White's Ford and moving on Frederick, which was occupied on the 6th, without resistance. Gen. Lee, with the rest of his army, rapidly followed, concentrating at Frederick; whence he issued the following seductive address: