ght me from Washington, that point being intended as my
headquarters while making preparations to advance. The enemy was
occupying Martinsburg, Williamsport, and Shepherdstown at the time;
sending occasional raiding parties into Maryland as far as
Hagerstown. The concentration of my troops at Halltown being an
indication to Early that we intended to renew the offensive, however,
he immediately began counter preparations by drawing in all his
detached columns from the north side of the Potomac, abandoning a
contemplated raid into Maryland, which his success against Crook at
Kernstown had prompted him to project, and otherwise disposing
himself for defense.

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 si