.]

Toward evening on Thursday, a thunderstorm and gale of wind came up,
adding greatly to the wretched discomfort of the troops for the
moment, but making the air clearer and laying the dust for a day or
two. I found partial shelter with my staff, on the veranda of a
small house which was occupied by ladies of the families of some
general officers of the Potomac Army, who had seized the passing
opportunity to see their husbands in the interval of the campaign.
We thought ourselves fortunate in getting even the shelter of the
veranda roof for the night. On Friday morning (29th), Captain Fitch,
my quartermaster, was able to report his train and baggage safe at
Alexandria, and we were ready for any service. Orders came from
General McClellan during the forenoon to move the four regiments now
with me into Forts Ramsey and Buffalo, on Upton's and Munson's
hills, covering Washington on the direct road to Centreville by
Aqueduct Bridge, Ball's Cross-Roads, and Fairfax C. H. [Footnote:
Official Records, vol. xii. pt. iii. pp. 712, 726. For this he had
Halleck's authority, in view of the danger of cavalry raids into the
city. _Id_., p. 722.] General McClellan had established his
headquarters on Seminary Ridge beyond the northern outskirts of
Alexandria, and after putting my command in motion I rode there to
get fuller instructions from him as to the duty assigned me. His
tents were pitched in a high airy situation looking toward the
Potomac on the east; indeed he had found them a little too airy in
the thunder-squall of the previous evening which had demolished part
of the canvas village. It must have been about noon when I
dismounted at his tent. The distant pounding of artillery had been
in our ears as we rode. It was Pope's battle with Jackson along the
turnpike between Bull Run and Gainesville and on the heights above
Groveton, thirty miles away.

[Illustration: Map]

General Franklin had ridden over from Annandale and was with
McClellan receiving his parting directions under the imperative
orders which Halleck had sent to push that corps out to Pope.
McClellan's words I was not likely to forget. "Go," he said, "and
whatever may happen, don't allow it to be said that the Army of the
Potomac failed to do its utmost for the country." McClellan then
explained to me the importance of the position to which I was
ordered. The heights were the outer line of defence of Washington on
the west, which had been held at one time, a