106 Southern Historical Society Papers.
pass which led to McLaws's rear until Harper's Ferry should fall. It was not General Lee's original intention to dispute the passage of South Mountain with McClellan. His design, on the other hand, was to induce the Federal army, if possible, to cross that range into the Hagerstown Valley, and when this army had thus gotten fairly out of the reach of Washington the Confederate commander expected to give it battle upon his own terms. And, judging from McClellan's character and movements, Lee believed he would have ample time for the reduction of Harper's Ferry and the reunion of his divided arm}' in the neighborhood of Hagerstown before McClellan would be ready to cross the mountain. Consequently D. H. Hill and Stuart were expected to delay McClellan's march until the operations at Harper's Ferry should be completed.
On the 13th of September a copy of General Lee's order, giving the proposed movements of every division in his army until it should be reunited after the capture of Harper's Ferry, fell into the hands of General McClellan at Frederick. The copy so captured was the one sent from General Lee's headquarters addressed to General D. H. Hill. How it was lost, and where, are not definitely knov/n. Gen- eral Hill states that he never received this copy of the order, and consequently it must have been lost through the carelessness of some one else, but we believe no means exist of tracing the history of this accident further. General Longstreet thinks that McClellan might have gotten through his own agencies all the information the order gave him ; but such a supposition is at variance with all the facts of the case. As Halleck's dispatches show, the movement of Confed erate troops to the south side of the Potomac was interpreted as a menace to Washington, and served simply to hamper McClellan. Nor could any agencies, even had they been vastly more efficient than usual, have revealed to McClellan the position for days to come of every part of Lee's army as well as the designs of its commander. McClellan, it is certain, valued the importance of the order infinitely higher than General Longstreet does. He gave vent to demonstra- tions of joy when he read it, and at once comprehended the oppor- tunity presented for striking his adversary a tremendous blow. By a prompt movement forward he might expect to overwhelm the small part of Lee's army in his front, and, turning down upon the rear of McLaws, might raise the siege of Harper's Ferry, and perhaps de- stroy a portion of the troops engaged in conducting it.
At once orders were issued to every part of the Federal army for a vigorous forward movement. Stuart found his cavalry pickets
