was made, by our men
springing, as if by magic, to the tops of the houses into which they had
patiently and quietly made their way with the bar and pick, and to the
utter surprise and consternation of the enemy, opening upon him, within
easy range, a destructive fire of musketry. A single discharge, in which
many of his gunners were killed at their pieces, was sufficient to drive
him in confusion from the breastworks; when a prolonged shout from our
brave fellows announced that we were in possession of the Garita of San
Cosme and already in the city of Mexico". (Ex. Doc. No. 1, p. 392.)

The American army having thus captured the fortifications of the capital
of the enemy's country, a magnificent city of nearly 200,000
inhabitants, a secure lodgement was immediately effected in large
houses, on the left of the street, a few hundred yards from the Garita.
I then proceeded, with the engineer company and an infantry detachment,
several hundred yards farther; and found a strong position, on the right
of the street where the troops could rest protected from fire. Going
farther to the front, I discovered that, 150 yards in advance there was
a large convent, on the left of the street, occupied by a strong force.
The next cross street, the Paseo, had batteries upon it. These facts
were reported to General Worth, who ordered forward two brigades--one to
occupy each of the positions selected--and, directed me to place those
troops, station the picket-guards, and then, with Lieutenant McClellan,
report at his headquarters which was several hundred yards within the
Garita.

The aqueduct, in the middle of the street along which we advanced, was
an open stone trough, supported at a height of ten feet, or more, by
pillars and arches. There was a good deal of firing down the street from
Mexican detachments; but, by taking shelter under the arches, between
the pillars, our men, in small groups, were quite well protected. A
little before dark, whilst I was under one of the arches at the extreme
front, endeavoring to get a closer view of the enemy at the convent and
on the Paseo, I was joined by Lieutenant Sydney Smith, of the Fourth
Infantry, who had borne several messages from me to General Worth during
the afternoon. In a few moments after he joined me we heard horses feet
rapidly approaching us from the direction of the citadel. These horsemen
were captured, and proved to be three Mexican officers, one of whom was
Adjutant-General o