The Battle of Palo Alto
Vera Cruz Scott organized the Regulars into a division, but before reaching Mexico City he had to reorganize his army anew due primarily to losses by disease and expiring enlistment terms. When more volunteers arrived, he formed his infantry into four divisions of two brigades each, with an artillery company supporting each brigade. He placed elements of three dragoon regiments in a brigade under Col. William S. Harney. Satisfied with his field dispositions, Scott attacked and then entered Mexico City on 13 September.[1]
During the course of the war both Taylor and Scott organized ad hoc divisions as combined arms teams. These underwent several reorganizations for a variety of reasons, including a lack of transportation for moving units and supplies, a need to establish and protect lines of communication, and a shortage of personnel to maintain units at some semblance of fighting strength. The war, nevertheless, brought about a new integration of infantry and field artillery within divisions, which operated as independent, maneuverable commands. The stock-trail gun carriage, adopted in 1836, was a technological breakthrough that gave US. field artillery in the Mexican War sufficient mobility and maneuverability for integration of the arms.[2]
The revised Army Regulations published in 1857 reflected the changes developed during the course of the war for combining the combat arms. Doctrine called for a division usually to consist of "two or three brigades, either infantry or
