In early September 1847, American forces managed to drive the Mexicans from their positions near the base of the Chapultepec Castle in the Battle of Molino de Rey. The castle guarded Mexico City from the west. Army engineers continued to express interest in the southern causeways into the city, and so General Winfield Scott held a council of war with his generals and engineers on 11 September. Scott favored attacking Chapultepec, but the only general to agree with him was General David E. Twiggs. Most of Scott’s remaining officers favored the attack through the southern gates, including (then) Captain Robert E. Lee. A young lieutenant by the name of P. G. T. Beauregard gave a textbook speech that caused Brigadier General Franklin Pierce to change his vote in favor of the western attack.
Inside the city, General Antonio Lopez de Santa Anna commanded the Army of Mexico. He understood Chapultepec was an important defense for the city. The castle stood atop a 200-foot hill that was the home of the Mexican Military Academy. Santa Anna’s field commander, however, General Nicolas Bravo, had fewer than 1,000 troops. The official records of Mexico indicate that there were only 400 defenders. All additional troops were used in external walled redoubts of the castle to protect the rectangular shaped parade ground in front of the castle itself. High walls extending about three-quarters of a mile long, but one quarter mile deep protected this entire area. This area was critical because the slope from the hill from the west was so gentle that it actually encompassed the southern slopes. Additionally, the source of water for the castle was located within this area.
General Scott organized two storming parties: Captain Samuel Mackenzie led 256 men from Major General Gideon J. Pillow’s division and Captain Silas Casey’s force from Major General John A. Quitman’s division. Mackenzie would advance from the Molino eastward up the hill; Casey would advance along the Tacubaya Road. At the last minute, U. S. Marine Corps Major Levi Twiggs replaced Captain Casey. Only General Twiggs division and (then) Brigadier General Bennett C. Riley’s brigade protected the American right flank.
The Battle of Chapultepec began with an artillery barrage at dawn on 12 September 1847. The assault continued all-day and halted at sundown. It resumed at first light on the following day. The barrage fell silent at 0800 and Scott ordered the infantry to make their attack. There were three columns in the attack formation: 11th and 14th Infantry under Colonel William Trousdale occupied the left flank; in the center were four companies of the Voltiguer regiment under command of Colonel Timothy Patrick Andrews and the 9th and 15th Infantry moving through the swamp and western edge of the grove, and on the right were the remaining four Voltiguer companies under Lieutenant Colonel Joseph E. Johnson.
General Pillow, although shot in the foot, called for reinforcements, which came from General Quitman. The attack faltered, however, when fired upon by the Moella Battalion artillery. Andrews’s column cleared the grove of Mexican troops and linked up with Johnson, but the attack by the 9th and 15th Infantry stalled waiting for scaling ladders. Colonel Ransom in command of the 9th Infantry was killed.
The assault continued when Quitman brought up the 1st Brigade under Brigadier General Persifor F. Smith, organizing him on the right, and directed Brigadier General James Shields and the New York and Pennsylvania regiments into the assault. Brigadier General Newman S. Clarke’s brigade arrived on the western slope (along with scaling ladders), and it wasn’t long before the Voltigeurs planted their flag on the parapet of the castle. An assault of 120 handpicked Marines and soldiers attacked the hill from the south; the fighting was hand-to-hand, up close and personal with fixed bayonets as Americans struggled up the steep hill. The small assault force reached the castle at around 0930 and raised an American flag over the fortress. Soon after, General Bravo surrendered to the New York Regiment. Santa Anna watched the Americans take Chapultepec; he is said to have remarked, “I believe if we were to plant our batteries in hell, the damned Yankees would take them from us.”
Side note: During the battle, thirty men from the Saint Patrick’s Battalion, a group of former US Army soldiers who joined the Mexican side, were executed. These men had been previously captured during the Battle of Churubusco and it was Colonel William S. Harney’s orders to hang them within Chapultepec—within full view of all hands, and at the precise moment the US flag replaced the Mexican tricolor atop the citadel.
General Scott arrived at the Chapultepec Castle and was mobbed by his soldiers. General Worth’s division was sent to support Trousdale’s men on the La Veronica Causeway (present day Avenida Melchor Ocampo) for the main attack against the San Cosme Gate. Trousdale, Garland, Clarke, and Cadwalader’s Brigades began their advance up the causeway.
General Quitman quickly reformed his troops in Chapultepec. Detailing the 15th Regiment to guard the castle and prisoners, he ordered a feint toward the Belen Causeway. The Morelia Battalion, commanded by General Andres Terres, manned the Belen Gate.
By the time Worth started his advance down the San Cosme, having fended off an attack by Mexican cavalry, it was 1600 (4 pm). Garland’s Brigade used the arches of the aqueduct to advance to the right. Clarke’s men passed on the right through a tunnel carved out by sappers.
Marine Captain George Terrett led First Lieutenant John Simms, Second Lieutenant Charles Henderson, and 36 leathernecks in pursuit of enemy troops as they fell back toward the city. Terrett and his Marines raced up the San Cosme causeway under heavy fire. Lieutenant Ulysses S. Grant and twenty soldiers of the 4th Infantry used the bell tower of San Cosme Church to place a mountain howitzer. On the north side Navy lieutenant Raphael Semmes duplicated Grant’s successful maneuver.
Lieutenants Simms and Henderson attacked the gate with 85 men but soon found the gate too heavily defended. Simms and Marine Second Lieutenant Jabez Rich led seven Marines in an attack from the left side of the gate while Lieutenant Henderson, even though wounded in the leg, launched a simultaneous attack from the front. Captain George Terrett, led a group of Marines behind the Mexican defenders and, climbing on the roof, unleashed a deadly volley on the artillery gunners. Altogether, the Americans seized the San Cosme Gate, sustaining six casualties. The Mexican defenders were now in full retreat, sweeping Santa Anna along with them as they fell back into the city and subsequently withdrew from the battle.
At dawn on 14 September, as Quitman and Worth prepared to assault the two entrances to the city, the Americans realized that Santa Anna had pulled out. Quitman’s men raced through the crowded streets into the Grand Plaza and took the Mexican National Plaza, where before had stood the Halls of Montezuma. Marines were stationed there to guard the palace, and when Scott marched into the city, he discovered the streets well secured.
Among the lower ranking American officers that participated in the Mexican American War, many served as general officers in the American Civil War. These included Daniel H. Hill, Ulysses S. Grant, George Pickett, James Longstreet, Thomas (Stonewall) Jackson, and Robert E. Lee. Officers who once served with one another in the crucible of combat turned against one another. It was nothing short of awful.
There is also another legacy: the performance of U. S. Marines in the Battle of Chapultepec and subsequent occupation of Mexico City, are memorialized by the opening verses of the United States Marine Corps hymn: “From the Halls of Montezuma….”
During the battle at Chapultepec, 90 percent of the Marine officers and noncommissioned officers who fought were killed —including their commander, Major Levi Twiggs. In honor of these officers and NCOs, Marine Corps tradition maintains that all officers and noncommissioned officers shall be entitled to wear a red stripe on the trousers of the Dress Blue Uniform. Commonly referred to as the blood stripe, it serves as a reminder to all Marines of the blood that was shed in the capture of Chapultepec.
 Fourteenth President of the United States
 Major Levi Twiggs was the younger brother of General David E. Twiggs. Levi commanded the U. S. Marines
 Meaning line or light infantry
 Charles Henderson was the son of then Marine Corps Commandant Colonel Archibald Henderson
 After Semmes lost his ship in a squall, he was assigned to fight with the Army.