Advance upon Mexico City
Santa Anna fled the Battle of Cerro Gordo in such a hurry that he left behind his artificial leg. The severe defeats the Mexican general had suffered severely undermined Mexican morale and civilian support for the war against the Americans. When Scott’s army approached the Mexican city of Puebla it surrendered without defense on the first of May. Scott paused at Puebla to rest his troops and replenish supplies for a push forward to Mexico City, as well as strengthen his lines of supply to Veracruz. Scott sent troops forward to reconnoiter, and patrolled the areas around Puebla against guerrilla bands, before moving forward again in August.
In all, Santa Anna had just less than 30,000 men in position to defend Mexico City, but they were spread over a wide area, and many were inexperienced troops. Scott’s army first made contact with the Mexicans on August 19 near Contreras. An American party building a road on which they could attack the Mexican town of San Antonio were attacked by elements of the Mexican Army, and both sides rushed reinforcements to the scene. The fighting raged until dark. During the night American patrols discovered a path which could be used to get around the Mexican troops and attack them from the rear. Their assault the following morning drove the Mexicans from the battlefield in fewer than twenty minutes.
The Mexican defenses reformed near Churubusco and on August 20 they were attacked by units of Scott’s army. Mexican troops occupied a convent and entrenched along its front. The fighting throughout the afternoon was ferocious, and the Mexicans gradually were reduced to those occupying the convent. Within the building were members of the unit known as the St. Patrick’s Battalion (San Patricios) who refused to allow the other units within the surrounded building to surrender, on at least three occasions pulling down white flags held aloft by men of other units. The battle continued until the Americans were ordered to halt.
The San Patricios did not continue the fight out of an excess of courage. The battalion was comprised mostly of American immigrants from Catholic countries, who had deserted the American Army, preferring to fight for Catholic Mexico. They feared that if they surrendered to the Americans they would be dealt with harshly, at the very least whipped for desertion, and possibly executed for treason. The battle for Churubusco led to the Americans taking over 1,600 prisoners, including three Mexican generals. The United States Army was in position to take Mexico City following the victory, though the fighting was not yet over.
The victory at Churubusco led to the opening of talks regarding an armistice, which continued until September 6. Despite the presence of the American Army outside of their capital city the Mexican commissioners were unwilling to concede the gains made by American troops and Scott, who had deliberately left Mexico City unscathed, was forced by Mexican intransigence to renew the assault on September 8. Santa Anna had used the armistice to prepare for additional fighting around the city. On September 8, 1847 the Americans and Mexican fought yet another bloody battle at Molino del Rey, on the outskirts of Mexico City.