The US declared war on Mexico in May 1846 and invaded Mexico on two different fronts. General Winfield Scott’s assault on Mexico City had been preceded by an amphibious assault and capture of the port of Vera Cruz in March 1847. The land invasion had been marked by a rout of the forces of the Mexican commander, Antonio Santa Anna, at Cerro Gordo in April and, as they closed on Mexico City, by quickfire victories at Contreras and Churusbusco in late August. Major Generals Worth and Quitman spearheaded the advance into the capital itself. Worth first seized the cannon foundry, Molino del Rey, on 8 September and prepared for an assault on the city gate at San Cosme. Following up, Quitman stormed the castle at Chapultepec on 13 September and moved on Belén Gate. Unbeknownst to the Americans, the Junta controlling the garrison decided at this point to evacuate the city. The Americans pushed on tentatively into the centre on 15 September, and, despite desultory sniper fire, occupied the city.
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