the resulting battle, the 5th Infantry broke a charge by Mexican lancers trying to break through to Taylor's supply train. Over night, the Mexicans withdrew to a better defensive position at Resaca de la Palma, which Taylor's army assaulted on the morning of the 9th. After stiff initial fighting, U.S. dragoons overran the Mexican artillery. The 5th and 8th Regiments then led a charge that broke the Mexican center and routed their army. Taylor's troops relieved Fort Texas, crossed the Rio Grande into undisputed Mexican territory and occupied Matamoros, where they spent most of the summer. In late August Taylor moved south toward Monterrey, arriving on 19 September 1846. The 5th Infantry was assigned to the division of Brigadier General William J. Worth. The Battle of Monterrey began on 21 September. David Twiggs' division assaulted the city, soon finding itself in house-to-house fighting, while Worth's division went around the city, cutting off its communications. On the 23rd, the 5th Infantry captured Fort Soldado, surrounding the Mexican forces. Worth's division also fought its way into the city, contributing to the Mexicans' decision to negotiate. They surrendered the city to Taylor in exchange for a two months' truce. After Monterrey, the 5th and the other regular regiments in Taylor's command were replaced by volunteers. They returned to Texas to join Major General Winfield Scott's expedition to Veracruz. The whole regiment was now together, though two companies were detached during the march to Mexico City and spent their time defending supply trains from guerilla attacks. Still in Worth's division, the 5th captured Perote on 22 April 1847. Reaching the outskirts of Mexico City, the 5th was part of the flanking movement that led to the victory at Contreras on 19 August. The following day, they took the right flank in the assault on the bridgehead at Churubusco. The 5th provided storming parties for the assaults on the Molino del Rey on 8 September and Chapultepec Castle on the 13th; the full regiment followed up in the latter seizure. Later on the 13th, the 5th joined in the seizure of the Garita San Cosme, one of the city gates of Mexico City itself. This led to the city's surrender on the 14th. 1848–61 In May 1848, after the United States Senate ratified the Treaty of Guadalupe Hidalgo, the 5th Infantry marched from Mexico City to Veracruz and returned to the United States. They spent