Battle of Chapultepec - Background

Background

On September 8, 1847, in the costly Battle of Molino del Rey, U.S. forces had managed to drive the Mexicans from their positions near the base of Chapultepec Castle guarding Mexico City from the west. However, Army engineers were still interested in the southern approaches to the city. General Winfield Scott held a council of war with his generals and engineers on September 11. Scott was in favor of attacking Chapultepec and only General David E. Twiggs agreed. Most of Scott's officers favored the attack from the south including Captain Robert E. Lee. A young lieutenant, Pierre Beauregard, gave a text book speech that persuaded General Pierce to change his vote in favor of the western attack.

Antonio López de Santa Anna was in command of the army at Mexico City. He understood that Chapultepec Castle was an important position for the defense of the city. The castle sat atop a 200-foot (60 m) tall hill which in recent years was being used as the Mexican Military Academy. General Nicolás Bravo, however, had fewer than 1,000 men (832 Total including 250 10th Infantry, 115 Querétaro Battalion, 277 Mina Battalion, 211 Union Battalion, 27 Toluca Battalion and 42 la Patria Battalion with seven guns) to hold the hill, including 200 cadets, some as young as 13 years old. A gradual slope from the castle down to the Molino del Rey made an inviting attack point.

According to military records at the General National Archives in Mexico City, Chapultepec Castle was only defended by 400 men, 300 from de Batallón de San Blas under the command of Lieutenant Colonel Felipe Xicoténcatl, and the castle's garrison of 100 men, including the cadets. The additional Mexican troops were used in external walled redoubts of the castle to protect a large rectangular piece of ground in front of the castle itself. This area was protected by high walls and was about three-quarters of a mile long by one-quarter mile deep. This area was critical to the defense of the castle because the slope of the hill from the west was so gentle, it also encompassed the southern slopes which were moderate compared to the steep escarpments on the east and north. Also the source of water for the castle was located within this area.

Scott organized two storming parties numbering 250 hand-picked men. The first party under Captain Samuel Mackenzie would lead Gideon Pillow's division from the Molino east up the hill. The second storming party was to be commanded by Captain Silas Casey to lead John A. Quitman's division against the southeast of the castle, but Casey was replaced by Major Levi Twiggs.