General Winfield Scott's army launched an assault on the fortified hill of Chapultepec, overlooking the Mexican capital, after days of bombardment. Mexican defenders, including military cadets later mythologized as the 'Niños Héroes,' fought desperately before the position fell, opening the road into Mexico City itself, which surrendered the next day and effectively ended major combat in the war.
Chapultepec Castle, home to Mexico's military academy, sat atop a steep hill guarding the western approach to Mexico City. American gunners bombarded it through September 12 before infantry scaled the slopes on the morning of the 13th, but the crucial preparatory assault and artillery duel that broke Mexican resistance occurred on the 12th, softening defenses manned by roughly 1,000 Mexican soldiers and cadets against Scott's numerically superior force.
Legend holds that six teenage cadets, the Niños Héroes, refused to retreat and died defending the castle, one allegedly wrapping himself in the Mexican flag and leaping from the ramparts rather than surrender it to the invaders. Whether entirely accurate or partly embellished by later nationalist memory, the story became foundational to Mexican patriotic identity.
The castle's fall exposed Mexico City to direct assault, and Scott's forces poured through the Belén and San Cosme gates. Within a day the capital fell, and Mexico's government fled, setting the stage for the punishing Treaty of Guadalupe Hidalgo that ceded nearly half of Mexico's territory to the United States.
Key people: Winfield Scott, Nicolás Bravo