officers of the engineer corps won special distinction. In fact, in
both cases, tasks which seemed difficult at first sight were made easier
for the troops that had to execute them than they would have been on an
ordinary field. The very strength of each of these positions was, by
the skill of the engineers, converted into a defence for the assaulting
parties while securing their positions for final attack. All the troops
with General Scott in the valley of Mexico, except a part of the
division of General Quitman at San Augustin Tlalpam and the brigade of
Garland (Worth's division) at San Antonio, were engaged at the battle of
Contreras, or were on their way, in obedience to the orders of their
chief, to reinforce those who were engaged. The assault was made on the
morning of the 20th, and in less than half an hour from the sound of the
advance the position was in our hands, with many prisoners and large
quantities of ordnance and other stores. The brigade commanded by
General Riley was from its position the most conspicuous in the final
assault, but all did well, volunteers and regulars.

From the point occupied by Garland's brigade we could see the progress
made at Contreras and the movement of troops toward the flank and rear
of the enemy opposing us. The Mexicans all the way back to the city
could see the same thing, and their conduct showed plainly that they did
not enjoy the sight. We moved out at once, and found them gone from our
immediate front. Clarke's brigade of Worth's division now moved west
over the point of the Pedregal, and after having passed to the north
sufficiently to clear San Antonio, turned east and got on the causeway
leading to Churubusco and the City of Mexico. When he approached
Churubusco his left, under Colonel Hoffman, attacked a tete-de-pont at
that place and brought on an engagement. About an hour after, Garland
was ordered to advance directly along the causeway, and got up in time
to take part in the engagement. San Antonio was found evacuated, the