Battle of Chapultepec

Background

By the summer of 1847 the war over Texas and the borderlands had moved to central Mexico. Winfield Scott had landed at Veracruz in March, won at Cerro Gordo and waited at Puebla for reinforcements. Leaving inadequate garrisons behind, he marched into the Valley of Mexico on 7–10 August with only 10,738 rank and file. After Contreras and Churubusco on 19–20 August cost him over a thousand men, an armistice failed, and on 8 September Worth's division took the Molino del Rey, a group of stone buildings at the foot of Chapultepec, for another 789.

Mexico City was ringed by a canal and approached only along raised causeways, each ending in a fortified gate. Scott surveyed the southern gates, judged them a net of obstacles, and decided on 11 September to swing round to the south-west and enter by the western gates instead. That meant first taking Chapultepec.

The hill, about 200 feet high, rose abruptly from the plain about a mile and a half from the city. On its summit stood the castle, which housed the Military College. A wall enclosed the hill and the old cypress grove at its foot. Mexican engineers had added a hornwork on the Tacubaya road, a ditch and breastworks along the grove, a redoubt halfway up, sandbags round the building and mines, three of them charged. Its guns commanded the roads from Tacubaya and the causeways to the Belén and San Cosme gates. Alcaraz and his co-authors, writing in 1848, thought it strong in appearance only and unable to stand a bombardment of two or three days.

The armies

Scott's army was small, tired and confident. Its four divisions were Worth's and Twiggs's regulars, Pillow's mixed division including the new Voltigeur regiment, and Quitman's volunteers (New York, South Carolina and Pennsylvania regiments) with a battalion of Marines. Its strength was its artillery and engineers. Captured Mexican pieces had trebled its siege train, and Captains Huger and Lee traced four heavy batteries within easy range of the castle. Its junior officers included Longstreet, Pickett, Thomas Jackson and Ulysses Grant.

Santa Anna still had far more men, perhaps 15,000 by McCaffrey's count, but many were raw National Guard or survivors of the August defeats, and he spread them across every gate he thought might be attacked, keeping a reserve under his own hand. Chapultepec was commanded by Nicolás Bravo, with José Mariano Monterde, director of the college, as his second. The garrison was under a thousand men from several battalions, with seven guns under Manuel Gamboa, plus the college's cadets, most of whom had been sent away before the assault. Estimates of how many stayed run from about 46 to more than a hundred, with recent graduates and staff. The San Blas battalion under Lieutenant Colonel Felipe Santiago Xicoténcatl was the only body sent to support them.

The battle

12 September: the bombardment. The American batteries opened early in the morning: Nos. 1 and 2 on the Tacubaya side supported by Quitman, Nos. 3 and 4 at the Molino supported by Pillow, with a mortar firing from the Molino's courtyard. Alcaraz says the fire ran from a little after five until seven in the evening. Walls were holed and roofs smashed; the corridor turned into a hospital filled with the dead, the wounded and the cadets. Santa Anna kept most of his men outside the works and towards the city, to avoid the fire and be ready for an assault, and refused Bravo's request for reinforcements until the hour of the storming.

13 September, dawn to about 09:30: the storming of the castle. This is the engagement CDB90 records as Chapultepec. The guns reopened at daybreak; at about 08:00 they fell silent, Scott's agreed signal. On the west, Pillow's division came out of the Molino through the grove, the Voltigeurs, 9th and 15th Infantry clearing sharpshooters from the trees. At the foot of the rocky slope Pillow was badly wounded and Cadwalader took over; Colonel Ransom was killed, and the attack stalled while the ladders came up. The 15th carried the midway redoubt. The Americans moved too fast for the mines to be fired: Lieutenant Alamán found the matches already in enemy hands. At the ditch and wall the storming party under Captain McKenzie planted its ladders; the first men up were thrown down, but a lodgement was made, and the Voltigeurs' Captain Barnard planted the first regimental colour. Lieutenant James Longstreet was wounded carrying the 8th Infantry's colours.

On the south-east, Quitman's column came up the Tacubaya causeway, cut and covered by batteries. The San Blas battalion, fighting at the foot of the hill, was outflanked and broken; Xicoténcatl was killed with most of his officers. Major Levi Twiggs of the Marines fell leading the second storming party. Persifor Smith's brigade swept right to take two road batteries, while the New York, South Carolina and 2nd Pennsylvania regiments crossed the ditched meadows and joined the final assault from the west. On the north, the 11th and 14th Infantry and Lieutenant Thomas Jackson's section of Magruder's battery took a one-gun breastwork. A New York company reached the roof, where some cadets were still firing, and Bravo surrendered. The American flag went up at about 09:30.

Midday to 14:00: the Belén gate. Scott intended Quitman only to threaten the Belén gate while Worth made the main attack by San Cosme. Quitman ignored repeated orders and pushed his whole division down the Belén causeway, the Mounted Rifles fighting on foot from arch to arch of the aqueduct. He took an intermediate battery and broke through the gate between 13:20 and 14:00, but was then pinned under the guns of the Ciudadela; Drum and Benjamin of the heavy battery were mortally wounded.

16:00 to evening: San Cosme. Worth beat off a sortie by about 1,500 of Torrejón's cavalry and started down the San Cosme causeway about 16:00, fighting through gardens and flat-roofed houses. Pioneers with pickaxes and crowbars broke through walls; Lieutenant Ulysses Grant hauled a mountain howitzer into a church belfry to fire on the defenders. Worth was through the outer defences by about 18:00 and had carried two batteries by 20:00, halting short of the final barrier for the night.

Aftermath

Scott's army lost 862 killed, wounded and missing on 12–14 September; Mexican losses are unknown, with estimates from about 1,800 killed and wounded to about 3,000. That night Santa Anna, judging the city lost, marched his remaining army out to the north. At about 04:00 on the 14th a city delegation told Scott the government and army had gone; he refused any capitulation, and Quitman raised the American flag over the National Palace. Released convicts and disbanded soldiers fired from rooftops for more than a day. Peace came only with the Treaty of Guadalupe Hidalgo in February 1848.

During the assault Colonel William Harney had thirty condemned men of the San Patricio Battalion, deserters from the US Army captured at Churubusco, stand on carts with nooses round their necks in sight of the castle, and hanged them when the American flag replaced the Mexican one, on Scott's orders.

In Mexico the battle is remembered through the Niños Héroes, the six young men honoured every 13 September. Alcaraz recorded in 1848 only that students were among the last defenders. Historians now hold that Juan Escutia was probably a soldier of the San Blas battalion, not a cadet, and that there is no evidence for his leap from the castle wrapped in the flag; the flag was taken and returned by the United States in 1952. The 1947 identification of their remains is disputed. In the United States, the Marines' Hymn's 'Halls of Montezuma' recalls the battle.

Wargaming it

Chapultepec is a classic assault-on-a-fortress game, and works best as two linked scenarios. The castle storm suits a regimental or battalion scale on a table about a metre and a half square: the walled grove, the rocky western slope, the midway redoubt, the ditch and wall at the summit, and the Tacubaya causeway on the south-east with its road batteries and ditched meadows. The American player has numbers, superb artillery and a strict clock; the Mexican player has a small, shaken garrison, seven guns and three mines whose firing should be a gamble.

The key mechanics are ladders and reserves. Storming columns should stall at the wall until the ladders arrive, as the 9th and 15th did. Santa Anna's reserves sit off-table and arrive only if the Mexican player commits them early, against the risk of a feint elsewhere. Twiggs's demonstration at the southern gates can be handled as a die roll that pins part of that reserve.

The second scenario, the causeways, is a street-fighting race down two parallel lanes of aqueduct arches: Quitman disobeying orders at Belén, Worth burrowing through houses at San Cosme against Torrejón's cavalry and rooftop riflemen. Good 'what ifs': Santa Anna reinforcing Bravo on the night of the 12th; the mines firing; Quitman obeying his orders and feinting.

Maps and pictures