Reunion of Virginia Division A. N. V. Asaociatian. 513
tain and Elk Ridge is Pleasant Valley. Along the base of the Blue Ridge in Virginia, the Shenandoah empties into the Potomac. At the confluence of the two rivers is Harpers Ferry. It is dominated on the Maryland side by the southern terminus of Elk Ridge, called Maryland Heights, and on the Virginia side by the northern end of Blue Ridge, known as Loudoun Heights. Harpers Ferry is, ol itself, a cul de sac, indefensible against the dominating heights on either side. Both Loudoun Heights and Maryland Heights are accessible from the rear by roads, and can be carried by a determined attack.
When Lee crossed into Maryland he knew that eleven thousand Federal troops were stationed at Winchester, Martinsburg and Har- pers Ferry. After he had crossed, he was informed that they had retired from Winchester. He supposed as he had a right to expect that they would evacuate the line of the Upper Potomac, and withdraw by way of Hagerstown into Pennsylvania. It is singular, but true, that whenever Lee anticipated his adversary's making a blunder he was never disappointed ; whenever he relied upon his acting upon sound rules of strategy his expectations always failed. So it was, that when he relied upon the evacuation of Harpers Ferry he found that he was entirely mistaken in his calculations.
On the 9th of September he learned that the forces in the Lower Valley had been concentrated at Harpers Ferry. In order to dis- pose of this threat upon his flank and rear, he at once set his army in motion, directing Major-General J. G. Walker to proceed by the Virginia side to occupy Loudoun Heights, Major-General McLaws, with Major-General R. H. Anderson, to take possession of Mary- land Heights, and Jackson, with the Second corps, to proceed by way of Williamsport and Martinsburg to invest Harpers Ferry, on the line between the Potomac and the Shenandoah. General Jack- son was directed to take charge of the movement, and the detached columns were ordered to be in position on Friday, the i2th. Long- street, with eleven brigades, and Hill, with five, were ordered to take position at Boonsboro, where the rest of the army was ordered to join them after the reduction of Harpers Ferry. At day-light, on the loth, his army moved, on the National road, from Frederick to Hagerstown. McClellan explains the tardiness of his movements, because, he says, his troops and trains moving on one road would have made a column fifty miles long. Lee found no such difficulty. His army swept along the broad turnpike in three close parallel columns, artillery and trains in the centre, and infantry on each side. 6
