given the task of gaining possession of the Saltillo road, and of
carrying the detached works outside the city, in that quarter. He
started on his march early in the afternoon of the 20th. The divisions
under Generals Butler and Twiggs were drawn up to threaten the east and
north sides of the city and the works on those fronts, in support of the
movement under General Worth. Worth's was regarded as the main attack on
Monterey, and all other operations were in support of it. His march
this day was uninterrupted; but the enemy was seen to reinforce heavily
about the Bishop's Palace and the other outside fortifications on their
left. General Worth reached a defensible position just out of range of
the enemy's guns on the heights north-west of the city, and bivouacked
for the night. The engineer officers with him--Captain Sanders and
Lieutenant George G. Meade, afterwards the commander of the victorious
National army at the battle of Gettysburg--made a reconnoissance to the
Saltillo road under cover of night.

During the night of the 20th General Taylor had established a battery,
consisting of two twenty-four-pounder howitzers and a ten inch mortar,
at a point from which they could play upon Black Fort. A natural
depression in the plain, sufficiently deep to protect men standing in it
from the fire from the fort, was selected and the battery established on
the crest nearest the enemy. The 4th infantry, then consisting of but
six reduced companies, was ordered to support the artillerists while
they were intrenching themselves and their guns. I was regimental
quartermaster at the time and was ordered to remain in charge of camp
and the public property at Walnut Springs. It was supposed that the
regiment would return to its camp in the morning.

The point for establishing the siege battery was reached and the work
performed without attracting the attention of the enemy. At daylight