d.
Nevertheless, at noon of the 13th McClellan had it in his power to
save the place and interpose his army between the two wings, of the
Confederates with decisive effect on the campaign. He saw that it
was an "emergency," but did not call upon his men for any
extraordinary exertion. Harper's. Ferry surrendered, and Lee united
the wings of his army beyond the Antietam before the final and
general engagement was forced upon him.

At my camp in front of Middletown, I received no orders looking to a
general advance on the 14th; but only to support, by a detachment,
Pleasonton's cavalry in a reconnoissance toward Turner's Gap.
Pleasonton himself came to my tent in the evening, and asked that
one brigade might report to him in the morning for the purpose. Six
o'clock was the hour at which he wished them to march. He said
further that he and Colonel Crook were old army acquaintances and
that he would like Crook to have the detail. I wished to please him,
and not thinking that it would make any difference to my brigade
commanders, intimated that I would do so. But Colonel Scammon,
learning what was intended, protested that under our custom his
brigade was entitled to the advance next day, as the brigades had
taken it in turn. I explained that it was only as a courtesy to
Pleasonton and at his request that the change was proposed. This did
not better the matter in Scammon's opinion. He had been himself a
regular officer, and the point of professional honor touched him. I
recognized the justice of his demand, and said he should have the
duty if he insisted upon it. Pleasonton was still in the camp
visiting with Colonel Crook, and I explained to him the reasons why
I could not yield to his wish, but must assign Scammon's brigade to
the duty in conformity with the usual course. There was in fact no
reason except the personal one for choosing one brigade more than
the other, for they were equally good. Crook took the decision in
good part, though it was natural that he should wish for an
opportunity of distinguished service, as he had not been the regular
commandant of the brigade. Pleasonton was a little chafed, and even
intimated that he claimed some right to name the officer and command
to be detailed. This, of course, I could not admit, and issued the
formal orders at once. The little controversy had put Scammon and
his whole brigade upon their mettle, and was a case in which a
generous emulation did no harm. What happened i