On April 12, Lieutenant Pierre G. T. Beauregard, of the United States Army Corps of Engineers, determined that possession of Atalaya Hill would enable the Mexican position to be turned. The Personal Memoirs of Ulysses S. Grant observe that, in order to determine whether a flanking movement was possible, "reconnaissances were sent out to find, or to make, a road by which the rear of the enemy's works might be reached without a front attack." These reconnaissances were made under the supervision of Captain Robert E. Lee and other officers, "all of whom attained rank and fame." Grant continues that it was the roadways constructed by the engineers which achieved victory: Twiggs' division took the hill on April 17, advancing up the slopes to El Telegrafo. Santa Anna reinforced El Telegrafo with Brigadier General Ciriaco Vasquez's 2d Light, 4th, and 11th Infantry. Captain Edward J. Steptoe set up his battery on Atalaya Hill and Major James C. Burnham set up a howitzer across the river. At 7:00 am on April 18, Twiggs directed William S. Harney's brigade to move against the front of El Telegrafo while Bennett C. Riley attacked from the rear. The combination easily took the hill, killing General Vasquez, and Captain John B. Magruder turned the Mexican guns on the retreating Mexicans. Simultaneously, James Shields' brigade attacked the Mexican camp and took possession of the Jalapa road. Once they realized they were surrounded, the Mexican commanders on the three hills surrendered and by 10:00 am, the remaining Mexican forces fled.
Aftermath
Santa Anna, caught off guard by the Fourth Regiment of the Illinois Volunteer Infantry, was compelled to ride off without his artificial leg, which was captured by U.S. forces and is still possession of the Illinois StateMilitary Museum in Springfield, Illinois. In the U.S. the prosthetic inspired song parodies. Showman P.T. Barnum claimed acquired it for display in his museum. The prosthetic was eventually donated to the state of Illinois, where it was displayed in its military museum. A visiting Mexican official was apparently embarrassed at seeing the trophy displayed, and it was removed. It was later the subject of controversy about its return to Mexico. Some cannons captured by Americans at Cerro Gordo were brought back to the United States as war trophies. The Third Regiment of Illinois Volunteers brought back a six-pound cannon where it was displayed temporarily in the Springfield Armory in Massachusetts, and whose current whereabouts are unknown. Scott moved on to Jalapa, and William J. Worth's division took San Carlos Fortress on April 22. Scott then occupied Puebla on 15 May, before departing for Mexico City on August 7.
Mexico was represented by the remnants of the Division of the North, totaling 5,650 personnel: 150 artillery, 4,000 infantry and 1,500 cavalry: including the Ampudia Brigade, the Vasquez Brigade and the Juvera Cavalry Brigade ; plus reinforcements from the Capitol: the Rangel Brigade, the Pinzon Brigade, and the Canalizo Special Cavalry Division. The 1,000-strong Artega Brigade, consisting of the Pueblo Activos and National Guard battalions, arrived at the end of the battle.
