Battle of Chapultepec The Battle of Chapultepec , in September 1847 , was a United States victory over Mexican forces holding Chapultepec Castle west of Mexico City during the Mexican - American War . Background . On September 8 , 1847 , in the costly Battle of Molino del Rey , U . S . forces had managed to drive the Mexicans from their positions near the base of Chapultepec Castle guarding Mexico City from the west . However , Army engineers were still interested in the southern approaches to the city . General Winfield Scott held a council of war with his generals and engineers on September 11 . Scott was in favor of attacking Chapultepec and only General David E . Twiggs agreed . Most of Scott ' s officers favored the attack from the south including Captain Robert E . Lee . A young lieutenant , P . G . T . Beauregard , gave a text book speech that persuaded General Pierce to change his vote in favor of the western attack . Antonio López de Santa Anna was in command of the army at Mexico City . He understood that Chapultepec Castle was an important position for the defense of the city . The castle sat atop a 200 - foot ( 60 m ) tall hill which in recent years was being used as the Mexican Military Academy . General Nicolás Bravo , however , had fewer than 1 , 000 men ( 832 : Total including 250 : 10th Infantry , 115 : Querétaro Battalion , 277 : Mina Battalion , 211 : Union Battalion , 27 : Toluca Battalion and 42 : la Patria Battalion with seven guns ( Gen . Manuel Gamboa with 2 - 24 lbs , 1 - 8 lb . , 3 - 4 lbs . & 1 howitzer ( 68 ) ) to hold the hill , including 200 cadets , some as young as 13 years old . A gradual slope from the castle down to the Molino del Rey made an inviting attack point . According to military records at the General National Archives in Mexico City , Chapultepec Castle was only defended by 400 men , 300 from de Batallón de San Blas under the command of Lieutenant Colonel Felipe Xicoténcatl , and the castle ' s garrison of 100 men , including the cadets . The additional Mexican troops were used in external walled redoubts of the castle to protect a large rectangular piece of ground in front of the castle itself . This area was protected by high walls and was about three - quarters of a mile long by one - quarter mile deep . This area was critical to the defense of the castle because the slope of the hill from the west was so gentle , it also encompassed the southern slopes which were moderate compared to the steep escarpments on the east and north . Also the source of water for the castle was located within this area . Scott organized two storming parties numbering 250 hand - picked men . The first party under Captain Samuel Mackenzie would lead Gideon Pillow ' s division from the Molino east up the hill . The second storming party was to be commanded by Captain Silas Casey to lead John A . Quitman ' s division against the southeast of the castle , but Casey was replaced by Major Levi Twiggs . Battle . The Americans began an artillery barrage against Chapultepec at dawn on September 12 . It was halted at dark and resumed at first light on September 13 . At 08 : 00 , the bombardment was halted and Winfield Scott ordered the charge . Following Captain Mackenzie ' s storming party were three assault columns from George Cadwalader ' s brigade of Pillow ' s division . On the left were the 11th and 14th regiments under Colonel William Trousdale , in the center were four companies of the Voltigeur regiment under Colonel Timothy Patrick Andrews , and on the right were the remaining four Voltigeur companies under Lieutenant Colonel Joseph E . Johnston . Pillow was quickly hit in the foot but ordered the attack forward . Andrews ' s column followed Mackenzie out of the Molino and cleared a cypress grove to the front of Mexican troops as Trousdale and Johnston moved up on the flanks . The attack stalled when Mackenzie ' s men had to wait for storming ladders to arrive , and there was a lull in the battle . To the southwest , 40 Marines led Captain Casey ' s storming party followed by James Shields ' brigade of volunteers north towards Chapultepec . Again the storming party stalled while waiting for ladders , and the rest of Shields ' men halted in the face of Mexican artillery . The scaling ladders arrived , and the first wave ascended the walls . In fact so many ladders arrived that 50 men could climb side by side . George Pickett ( later famous for " Pickett ' s Charge " and the Battle of Five Forks during the American Civil War ) was the first American to top the wall of the fort , and the Voltigeurs soon planted their flag on the parapet . Colonel Trousdale ' s column supported by Lieutenant Thomas J . Jackson ' s artillery faced superior numbers of Mexicans in a spirited defense . Newman S . Clarke ' s brigade brought new momentum to the fight on Pillow ' s front . General Shields was severely wounded when his men poured over the walls , but his troops managed to raise the U . S . Flag over the castle . Caught between two fronts , General Bravo ordered a retreat back to the city . Before he could withdraw , Bravo was taken prisoner by Shields ' New York volunteers . The Mexicans retreated at night down the causeways leading into the city . Santa Anna watched the Americans take Chapultepec while an aide exclaimed " let the Mexican flag never be touched by a foreign enemy " . Los Niños Héroes . During the battle , six Mexican military cadets refused to fall back when General Bravo finally ordered retreat and fought to the death . These were teniente ( lieutenant ) Juan de la Barrera and cadets Agustín Melgar , Juan Escutia , Vicente Suárez , Francisco Márquez and Fernando Montes de Oca , all between the ages of 13 and 19 . According to legend , the last of the six , Juan Escutia , grabbed the Mexican flag , wrapped it around himself and jumped off the castle point to prevent the flag from falling into enemy hands . In 1967 , Gabriel Flores painted a mural depicting " Los Niños Héroes " . A mural decorates the ceiling of the palace , showing Juan Escutia wrapped in the flag , apparently falling from above . A monument stands in Chapultepec Park commemorating their courage . The cadets are eulogized in Mexican history as " Los Niños Héroes " , the " Child Heroes " or Heroic Cadets . Saint Patrick ' s Battalion . Thirty men from the Saint Patrick ' s Battalion , a group of former United States Army soldiers who joined the Mexican side , were executed " en masse " during the battle . They had been previously captured at the Battle of Churubusco . Colonel William S . Harney specified that they were to be hanged with Chapultepec in view and that the precise moment of their death was to occur when the U . S . flag replaced the Mexican tricolor atop the citadel . Belén and San Cosmé Gates . General Scott arrived at the castle and was mobbed by cheerful soldiers . He detached a regiment to garrison Chapultepec and guard the prisoners there . Scott then planned for the attack on the city . He ordered a secondary attack against the Belén Gate and brought up the rest of William J . Worth ' s division to support Trousdale ' s men on La Verónica Causeway ( now Avenida Melchor Ocampo ) for the main attack against the San Cosme Gate . Defended by Gen . Rangel Granaderos Battalion , part Matamoros , Morelia & Santa Anna Battalions ( Col . Gonzalez ) , part 3d Light ( Lt . Col . Echeagaray ) , & 1st Light ( Comdt Marquez ) Trousdale , followed by John Garland ' s , Newman Clarke ' s and George Cadwalader ' s brigades , began advancing up the causeway . However , General Quitman quickly gathered the troops in Chapultepec and Persifor F . Smith ' s brigade turned east and immediately headed down the Belén Causeway . Intended only to be a feint , Quitman ' s attack soon became the center of the attack as he chased Chapultepec ' s retreating defenders back into the city . His troops were met by strong resistance in front of the gate , which was supported by a battery of artillery . Using the stone arches of the aqueduct running down the center of the causeway , Quitman ' s men crept forward . General Andrés Terrés ' troops ( three guns and 200 men : 2d Mexico Activos ) began to desert and flee back to the citadel . Led by the Mounted Rifles ( fighting on foot ) , Quitman breached the Belén Gate at 1 : 20 p . m . General Scott later commented " Brave Rifle , Veterans , you have been baptized in fire and blood and come out steel " . To the north , Robert E . Lee led Worth ' s attackers down the La Verónica Causeway . It was 4 p . m . by the time Worth reached the junction of the La Verónica and San Cosme causeways , where he beat back a counter attack of 1 , 500 cavalry before turning east down the San Cosme causeway . Progress was slow , and casualties were mounting . Finding the buildings alongside the roadway filled with enemy troops , Colonels Garland and Clarke were sent with the 1st and 2nd brigades to approach the defenses under cover by burrowing through the buildings on both sides with crowbars and pickaxes . Lieutenant Ulysses S . Grant discovered the bell tower of San Cosme Church south of the causeway , where he mounted the howitzer and began firing shots down onto the defenders from his lofty position . On the north side of the road , naval officer Raphael Semmes repeated Grant ' s successful maneuver . Lieutenant George Terrett then led a group of Marines behind the Mexican defenders and , climbing to the roof , unleashed a deadly volley on the artillery gunners . By 6 p . m . , Worth had broken through the gate , and the defenders scattered . Many retreated to the ciudadela , sweeping Santa Anna along with them . As night fell , Worth lobbed five mortar s into the city which fell near the National Palace . Aftermath . The battle had been a significant victory for the U . S . Lasting throughout most of the day , the fighting had been severe and costly . Generals Twiggs , Pillow , and Shields had all been wounded as well as Colonel Trousdale . The heaviest losses occurred during Quitman ' s attack on the Belén Gate . Every member of Quitman ' s staff lost his life in the close fighting on the causeway . Santa Anna lost General Bravo as a prisoner of war , and General Juan N . Pérez was killed . In a fit of rage Santa Anna slapped General Terrés and relieved him of command for losing the Belén Gate . In his memoirs Santa Anna branded Terrés as a traitor and made him the scapegoat for the defeat at Mexico City . Legacy . The efforts of the U . S . Marines in this battle and subsequent occupation of Mexico City are memorialized by the opening lines of the Marines ' Hymn , " From the Halls of Montezuma . . . " . Marine tradition maintains that the red stripe is worn on the trousers of the Blue Dress uniform , commonly known as the blood stripe , because all of the Marine NCOs and officers of the detachment died while storming the castle of Chapultepec in 1847 , though iterations of the stripe predate the war . In 1849 , the stripes were changed to a solid red from dark blue stripes edged in red , which dated from 1839 . In 1947 , President Harry S . Truman laid a wreath on the Cadets Monument as a gesture of goodwill after Mexico aided the U . S . in World War II . Among the lower - ranking officers present , many became generals in the upcoming American Civil War including Ulysess Grant , George Pickett , James Longstreet , Thomas Jackson ( Stonewall Jackson ) , and Robert E . Lee .