At Harper’s Ferry I made my headquarters in the second story of a small and very dilapidated hotel, and as soon as settled sent for Lieutenant John R. Meigs, the chief engineer officer of the command, to study with him the maps of my geographical division.  It always came rather easy to me to learn the geography of a new section, and its important topographical features as well; therefore I found that, with the aid of Meigs, who was most intelligent in his profession, the region in which I was to operate would soon be well fixed in my mind.  Meigs was familiar with every important road and stream, and with all points worthy of note west of the Blue Ridge, and was particularly well equipped with knowledge regarding the Shenandoah Valley, even down to the farmhouses.  He imparted with great readiness what he knew of this, clearly pointing out its configuration and indicating the strongest points for Confederate defense, at the same time illustrating scientifically and forcibly the peculiar disadvantages under which the Union army had hitherto labored.

The section that received my closest attention has its northern limit along the Potomac between McCoy’s ferry at the eastern base of the North Mountain, and Harper’s Ferry at the western base of the Blue Ridge.  The southern limit is south of Staunton, on the divide which separates the waters flowing into the Potomac from those that run to the James.  The western boundary is the eastern slope of the Alleghany Mountains, the eastern, the Blue Ridge; these two distinct mountain ranges trending about southwest inclose a stretch of quite open, undulating country varying in width from the northern to the southern extremity, and dotted at frequent intervals with patches of heavy woods:  At Martinsburg the valley is about sixty miles broad, and on an east and west line drawn through Winchester about forty-five, while at Strasburg it narrows down to about twenty-five.  Just southeast of Strasburg, which is nearly midway between the eastern and western walls of the valley, rises an abrupt range of mountains called Massanutten, consisting of several ridges which extend southward between the North and South Forks of the Shenandoah River until, losing their identity, they merge into lower but broken ground between New Market and Harrisonburg.  The Massanutten ranges, with their spurs and hills, divide the Shenandoah Valley into two valleys, the one next the Blue Ridge being called the Luray, while that next the North Mountain retains the name of Shenandoah.

A broad macadamized road, leading south from Williamsport, Maryland, to Lexington, Virginia, was built at an early day to connect the interior of the latter State with the Chesapeake and Ohio canal, and along this road are situated the principal towns and villages of the Shenandoah Valley, with lateral lines of communication extending to the mountain ranges on the east and west.  The roads running toward the Blue Ridge are nearly