At the termination of the armistice the position of the American forces was greatly changed from what it had been on the morning of the 20th of August. The occupation of San Agustin had been followed by that of Contreras, San Angel, Coyoacan and Churubusco in the course of that day, and on the next, Mixcoac and Tacubaya were taken possession of. Thus the whole southern and south-western portion of the valley, in front of Mexico, were now held by the Americans; and this disposition of their forces, commanding most of the principal approaches to the capital, enabled them, for the first time to select their point of attack.

In reconnoitering the chief outworks of the Mexicans by which he was still opposed, General Scott found that there were several of great importance. Directly north of his headquarters at Tacubaya, and distant about a mile, arose the lofty, isolated hill of Chapultepec, surrounded by its massive edifice, half castle, half palace, crowned with cannon. This point, it was known, had been strongly fortified to maintain the road leading from Tacubaya to the garita of San CosmÉ on the west of the city. Westwardly, beyond the hill of Chapultepec, whose southern side and feet are surrounded by a dense grove of cypresses, and on a rising ground within the military works designed to strengthen the castle, was the Molino del Rey, or King's Mill, which was represented to be a cannon foundry to which large quantities of church bells had been sent to be cast into guns. Still further west, but near the Molino or Mill, was the fortified Casa Mata, containing a large deposit of powder. These,—together with the strong citadel, lying near the garita of Belen in the south-western corner of the city,—were the principal external defences still remaining beyond the immediate limits of the capital. The city itself stands on a slight swell between lake Tezcoco and the western edge of the valley, and, throughout its greater extent, is girdled by a ditch or navigable canal extremely difficult to bridge in the face of an enemy, which serves the Mexicans not only as a military defence but for drainage and protection of their customs. Each of the eight strong city gates were protected by works of various character and merit. Outside and within the cross fires of these gates there were other obstacles scarcely less formidable towards the south. The main approaches to the city across the flat lands of the basin are raised on causeways flanked by wide and deep ditches designed for their protection and drainage. These causeways, as well as the minor cross roads which are similarly built, were cut in many places and had their bridges destroyed so as to impede the American's advance and to form an entangling net work; while the adjacent meadows were in this rainy season either filled with water in many places or liable to be immediately flooded by a tropical storm.

With these fields for his theatre of action, and these defences still in front of him, it was an important and responsible question, whether General Scott should attack Mexico on the west or on the south.

There can be hardly a doubt that the capture of the hill and castle of Chapultepec, before assaulting the city, was imperatively demanded by good generalship. If the capital were taken first, the Mexicans instead of retreating towards Guadalupe and the north, when we attacked and captured from the south, would of course retire to the avoided stronghold of Chapultepec; and, if our slender forces were subsequently obliged to leave the city in order to take the fortress, our sick, wounded and thinned regiments would be left to the mercy of the mob and the leperos. Chapultepec would thus become the nucleus and garrison of the whole Mexican army, and we might be compelled to fight two battles at the same time,—one in the city, and the other at the castle. But, by capturing the castle first, and seizing the road northward beyond it, we possessed all the most important outworks in the lap of the valley, and cut off the retreat of the Mexicans from the city either to the west, to the castle, or towards our rear in the valley. We obtained, moreover, absolute command of two of the most important entrances to the capital, inasmuch as from the eastern foot of the hill of Chapultepec two causeways, and aqueducts raised on lofty arches, diverged northeastwardly and eastwardly towards the city. The northernmost of these entered Mexico by the garita of San CosmÉ, while the other reached it by that of Belen near the citadel.

In attacking Chapultepec, it was important to consider the value of the Molino del Rey or King's Mill, and Casa Mata, both of which, as we noticed, lie on rising ground within the works designed to protect Chapultepec. Upon examination it will be found that the Molino del Rey, or King's Mill, bears the relation of a very strong western outwork both to the castle of Chapultepec and its approaches by the inclined plain which serves to ascend its summit. As the Molino del Rey is commanded and defended by the castle, so it reciprocally, commands and defends the only good approach to the latter. [74] As long as the Molino was held by the Mexicans, it would of course, form an important stronghold easily reached from the city around the rear of Chapultepec; so that if Scott attacked the castle and hill from the south, where the road that ascends it commenced, he would be in danger of an attack on his left flank from the Mexicans in the defences at Molino and Casa Mata.

If the King's Mill fell, the result to the enemy would be that, in addition to the loss of an important outwork and the consequent weakening of the main work, its occupants or defenders would be driven from a high position above the roads and fields into the low grounds at the base of Chapultepec, which were completely commanded from the Molino, and thus the Mexicans would be unable to prevent the American siege pieces from taking up the most favorable position for battering the castle. It was important, therefore, not only that the foundry should be destroyed, but, in a stratagetic view, it was almost indispensable in relation to future operations that the position should be taken. It is undeniable, as following events showed, that the Mexicans regarded it as one of their formidable military points. The capture of Chapultepec and the destruction of the post at Molino del Rey were, accordingly, determined on as preliminary to the final assault upon the city.

*****

As soon as the armistice was terminated bold reconnoissances were made by our engineers in the direction of Chapultepec and the Molino or King's Mill and Casa Mata. On the 7th of September Santa Anna's answer to Scott's despatch was received, and on the same day the Commander-in-Chief and General Worth examined the enemy's formidable dispositions near and around the castle-crowned hill. The Mexican array was found to consist of an extended line of cavalry and infantry, sustained by a field battery of four guns, either occupying directly or supporting a system of defences collateral to the castle and summit; but as the lines were skilfully masked a very inadequate idea of the extent of the forces was obtained. Captain Mason's reconnoissance on the morning of the same day, represented the enemy's left as resting on and occupying the group of strong stone buildings at the Molino adjacent to the grove at the foot of Chapultepec and directly under the castle's guns. The right of his line rested on the Casa Mata, at the foot of the ridge sloping gradually to the plain below from the heights above Tacubaya; while, midway between these buildings, were the field battery and infantry forces disposed on either side to support it. This reconnoissance indicated that the centre was the weak point of the position, and that its left flank was the strongest. In the Mill or Molino, on the left, was the brigade of General Leon, reinforced by the brigade of General Rangel; in the Casa Mata, on the right, was the brigade of General Perez; and on the intermediate ground was the brigade of General Ramirez, with several pieces of artillery. The Mexican reserve was composed of the 1st and 3d light, stationed in the groves of Chapultepec, while the cavalry consisting of 4,000 men, rested at the hacienda of Morales, not very far from the field. Such was the arrangement of the Mexican forces made by Santa Anna in person on the 7th of September, though it has been alleged by Mexican writers that it was somewhat changed during the following night. The wily chief had not allowed the time to pass during the negotiation between Trist and the Commissioners in political discussion alone. Regarding the failure of the treaty as most probable, he had striven to strengthen once more the military arm of his nation, and the first result of this effort was demonstrated in his disposition of troops at El Molino del Rey. The Americans' attack upon Chapultepec, as commanding the nearest and most important access to the city had been foreseen by him as soon as the armistice ended, and as a military man, he well knew that the isolated hill and castle could not be protected by the defenders within its walls alone or by troops stationed either immediately at its base or on the sloping road along its sides.

General Scott's plan of assault upon the city seems now to have been matured, though it required several days for full development according to the reconnoissances of his engineers. He designed to make the main assault on the west and not on the south of the city. Possessing himself suddenly of the Molino del Rey and the adjacent grounds he was to retire after the capture without carrying Chapultepec, the key of the roads to the western garitas of San CosmÉ and Belen. The immediate capture of Chapultepec would have been a signal to Santa Anna to throw his whole force into the western defence of the city; but by retiring, after the fall of the Molino or King's Mill, and by playing off skilfully on the south of the city in the direction of the garita of San Antonio Abad, Scott would effectually divert the attention of the Mexicans to that quarter and thus induce them to weaken the western defences and strengthen the southern. At length, at the proper moment, by a rapid inversion of his forces from the south to the west, he intended to storm the castle-crowned hill, and rush along the causeways to the capital before the enemy could recover his position.

*****

In pursuance of this plan, an attack upon El Molino del Rey and La Casa Mata was the first great work to be accomplished, and as soon as Santa Anna's reply closing the armistice was received on the 7th the advance towards that place was ordered for the following morning. This important work was entrusted to General Worth, whose division was reinforced by three squadrons of dragoons; one command of 270 mounted riflemen under Major Sumner; three field pieces under Captain Drum; two twenty-four pounders under Captain Huger, and Cadwallader's brigade 784 strong. The reconnoissances had been completed; at three o'clock in the morning of the 8th of September the several columns were put in motion on as many different routes, and when the gray dawn enabled them to be seen they were as accurately posted as if in midday for review. Colonel Duncan was charged with the general disposition of the artillery, while the cavalry were under Major Sumner.

At the first glimmer of day Huger's powerful guns saluted the walls of El Molino and continued to play in that quarter until this point of the enemy's line became sensibly shaken. At that moment the assaulting party, commanded by Wright of the 8th Infantry, dashed forward to assault the centre. Musketry and cannister were showered upon them by the aroused enemy, but on they rushed, driving infantry and artillerists at the point of the bayonet, capturing the field pieces and trailing them on the flying foe, until the Mexicans perceiving that they had been assailed by a mere handful of men suddenly rallied and reformed. In an instant the reassured and gallant foe opened upon the Americans a terrific fire of musketry, striking down eleven out of the fourteen officers who composed the command, and, for the time, staggering the staunch assailants. But this paralysis continued for an instant only. A light battalion which had been held to cover Huger's battery, commanded by Captain E. Kirby Smith, rushed forward to support, and executing its bloody task amid horrible carnage, finally succeeded in carrying the line and occupying it with our troops. In the meanwhile Garland's brigade, sustained by Drum's artillery assaulted the enemy's left near the Molino, and after an obstinate contest drove him from his position under the protecting guns of Chapultepec. Drum's section and Huger's battering guns advanced to the enemy's position, and his captured pieces were now opened on the retreating force. While these efforts were successfully making on the Mexican centre and left, Duncan's battery blazed on the right, and Colonel Mackintosh was ordered to assault that point. The advance of his brigade soon brought it between the enemy and Duncan's guns, and their fire was of course discontinued. Onwards sternly and steadily moved the troops towards the Casa Mata, which, as it was approached, proved to be a massive stone work surrounded with bastioned entrenchments and deep ditches, whence a deadly fire was delivered and kept up without intermission upon our advancing troops until they reached the very slope of the parapet surrounding the citadel. The havoc was dreadful. A large proportion of the command was either killed or wounded; but still the ceaseless fire from the Casa Mata continued its deadly work, until the maimed and broken band of gallant assailants was withdrawn to the left of Duncan's battery where its remnants rallied. Duncan and Sumner had meanwhile been hotly engaged in repelling a charge of Mexican cavalry on the left, and having just completed the work, the brave Colonel found his countrymen retired from before the Casa Mata and the field again open for his terrible weapons. Directing them at once upon the fatal fort he battered the Mexicans from its walls, and as they fled from its protecting enclosure he continued to play upon the fugitives as relentlessly as they had recently done upon Mackintosh and his doomed brigade.

The Mexicans were now driven from the field at every point. La Casa Mata was blown up by the conquerors. Captured ammunition and cannon moulds in El Molino were destroyed. And the Americans, according to Scott's order previous to the battle, returned to Tacubaya, with three of the enemy's guns, (a fourth being spiked and useless,) eight hundred prisoners including fifty-two commissioned officers, and a large quantity of small arms, with gun and musket ammunition. Three thousand two hundred and fifty-one Americans, had on this day, driven four times their number from a selected field; but they had paid a large and noble tribute to death for the victory. Nine officers were included in the one hundred and sixteen of our killed, and forty-nine officers in the six hundred and sixty-five of our wounded. The Mexicans suffered greatly in wounded and slain, while the gallant General Leon and Colonel Balderas fell fighting bravely on the field of battle. [75]

*****

The battle was over by nine o'clock in the morning. The Americans, after collecting their dead and wounded, retired from the bloody field, but they were not allowed to mourn over their painful losses. They had suffered severely, yet the battle had been most disastrous to the Mexicans. The fine commands of Generals Perez and Leon and of Colonel Balderas, were broken up; the position once destroyed, could not serve for a second defence, and the morale of the soldiers had suffered. The Mexicans were beginning to believe that mere formidable masses, if not directed by skilful chiefs, were, in truth, but harmless things, and not to be relied on very confidently for national defence. The new levies, the old regular army, and the volunteers of the city, had all been repeatedly beaten in the valley both before and since the armistice. Nevertheless, Santa Anna, in spite of all these defeats and disasters at the Molino and Casa Mata, caused the bells of the city to be merrily rung for a victory, and sent forth proclamations by extraordinary couriers, in every direction, announcing the triumph of Mexican valor and arms!

On the morning of the 11th, Scott proceeded to carry out the remainder of his projected capture of the capital. His troops had been already for some time hovering around the southern gates, and he now surveyed them closely covered by General Pillow's division and Riley's brigade of Twigg's command, and then ordered Quitman from Coyoacan to join Pillow by daylight, before the southern gates. By night however, the two Generals with their commands were to pass the two intervening miles between their position and Tacubaya where they would unite with Worth's division, while General Twiggs was left, with Riley, Captain Taylor and Steptoe, in front of the gates to manoeuvre, threaten, or make false attacks so as to occupy and deceive the enemy. General Smith's brigade was halted in supporting distance at San Angel, in the rear, till the morning of the 13th, so as to support our general depot at Mixcoac. This stratagem against the south was admirably executed throughout the 12th and until the afternoon of the 13th, when it was too late for Santa Anna to recover from his delusion.

In the meanwhile preparations had been duly made for the operations on the west by the capture of Chapultepec. Heavy batteries were established and the bombardment and cannonade under Captain Huger, were commenced early on the morning of the 12th. Pillow and Quitman had been in position, as ordered, since early on the night of the 11th, and Worth was now commanded to hold his division in reserve near the foundry to support Pillow, while Smith was summoned to sustain Quitman. Twiggs still continued to inform us with his guns that he held the Mexicans on the defensive in that quarter and kept Santa Anna in constant anxiety. Scott's positions and strategy perfectly disconcerted him. One moment on the south—the next at Tacubaya—then reconnoitering the south again—and, at last, concentrating his forces so that they might be easily moved northward to Chapultepec or southward to the gate of San Antonio Abad. These movements rendered him constantly sensible of every hour's importance, yet he would not agree with the veteran Bravo who commanded Chapultepec and was convinced that the hill and castle would be the points assailed. During the whole of the 12th the American pieces, strengthened by the captured guns, poured an incessant shower of shot into the fortress until nightfall, when the assailants slept upon their arms, to be in position for an early renewal on the 13th.

At half-past five in the morning the American guns recommenced upon Chapultepec; but still Santa Anna clung to the southern gates while Scott was silently preparing for the final assault according to a preconcerted signal. About 8 o'clock, judging that the missiles had done the work, the heavy batteries suddenly ceased firing, and instantaneously Pillow's division rushed forward from the conquered Molino del Rey, and overbearing all obstacles, and rapidly clambering up the steep acclivities, raised their scaling ladders and poured over the walls. [76]

Quitman, supported by Generals Shields and Smith, was meanwhile advancing rapidly towards the south-east of the works, over a causeway with cuts and batteries defended by an army strongly posted outside the works towards the east. But nothing could resist the impulse of the storming division, though staunchly opposed and long held at bay, and whilst it rushed to complete the work, the New York, South Carolina, and Pennsylvania volunteers, under Shields, crossed the meadows in front amid a heavy fire, and entered the outer enclosure of Chapultepec in time to join the enterprise from the west. The castle was now possessed at every point. The onslaught had been so rapid and resistless, that the Mexicans stood appalled as the human tide foamed and burst over their battlements. Men who had been stationed to fire the mines either fled or were shot down. Officers fell at their posts, and the brave old Bravo, fighting to the last, was taken prisoner with a thousand combatants.

Santa Anna was at last undeceived. He detached at once the greater portion of his troops from near the garita of San Antonio Abad; but it was too late;—the key to the roads of San CosmÉ and Belen had fallen; the advance works were weak, and the routed troops of Chapultepec fled rapidly along the causeways and over the meadows. Still as they retreated they fought courageously, and as our men approached the walls, the fresh troops in the neighborhood poured their volleys from behind parapets, windows and steeples. Nevertheless, Santa Anna dared not withdraw all his forces in the presence of Twigg's threatening division on the south.

Meanwhile Worth had seized the causeway and aqueduct of San CosmÉ, while Quitman advanced by the other towards the garita of Belen. The double roads on each side of these aqueducts which rested on open arches spanning massive pillars, afforded fine points for attack and defence. Both the American Generals were prompt in pursuing the retreating foe, while Scott, who had ascended the battlements of Chapultepec and beheld the field spread out beneath him like a map, hastened onward all the stragglers and detachments to join the flushed victors in the final assault.

Worth speedily reached the street of San CosmÉ and became engaged in desperate conflict with the enemy from the houses and defences. Ordering forward Cadwallader's brigade with mountain howitzers, preceded by skirmishers and pioneers with pick-axes and crow bars to force windows and doors and to burrow through the walls, he rapidly attained an equality of position with the enemy; and by 8 o'clock in the evening, after carrying two batteries in this suburb, he planted a heavy mortar and piece of artillery from which he might throw shot and shells into the city during the night. Having posted guards and sentinels and sheltered his weary men, he at length found himself with no obstacle but the gate of San CosmÉ between his gallant band and the great square of Mexico.

The pursuit by Quitman on the road to the gate of Belen had been equally hot and successful. Scott originally designed that this General should only manoeuvre and threaten the point so as to favor Worth's more dangerous enterprise by San CosmÉ. But the brave and impetuous Quitman, seconded by the eager spirits of his division, longing for the distinction of which they had been hitherto deprived, heeded neither the external defences nor the more dangerous power of the neighboring citadel. Onward he pressed his men under flank and direct fires;—seized an intermediate battery of two guns;—carried the gate of Belen,—and thus, before two o'clock, was the first to enter the city and maintain his position with a loss proportionate to the steady firmness of his desperate assault. After nightfall, he added several new defences to the point he had won so gloriously, and sheltering his men as well as he was able, awaited the return of daylight under the guns of the formidable and unsubdued citadel.

So ended the battles of the 13th of September, 1847, and so, in fact, ended the great contests of the war. Santa Anna had been again "disconcerted" in his plan of battle, by Scott, as he had previously been thwarted by Valencia's disobedience and wilfulness. Scott would not attack the south of the city where he expected him, and consequently the American chief conquered the point where he had not expected him!

When darkness fell upon the city a council of disheartened officers assembled in the Mexican citadel. After the customary crimination and recrimination had been exhausted between Santa Anna and other officers, it was acknowledged that the time had come to decide upon future movements. Beaten in every battle, they now saw one American General already within the city gate, while another was preparing to enter on the following morning, and kept the city sleepless by the loud discharges of his heavy cannon or bursting bombs as they fell in the centre of the capital. General Carrera believed the demoralization of his army complete. Lombardini, Alcorta and Perez coincided in his opinion, and Santa Anna at length closed the panic stricken council by declaring that Mexico must be evacuated during the night and by naming Lombardini General-in-Chief, and General Perez second in command. Between eight and nine o'clock SeÑor Trigueros called at the citadel with his coach, and bore away the luckless military President to the sacred town of Guadalupe Hidalgo, three miles north of the capital.

The retreat of the Mexican army began at midnight, and not long after, a deputation from the Ayuntamiento, or City Council, waited upon General Scott with the information that the federal government and troops had fled from the capital. The haggard visitors demanded terms of capitulation in favor of the church, the citizens and the municipal authorities. Scott refused the ill-timed request, and promising no terms that were not self imposed, sent word to Quitman and Worth to advance as soon as possible on the following morning, and, guarding carefully against treachery, to occupy the city's strongest and most commanding points. Worth was halted at the Alameda, a few squares west of the Plaza, but Quitman was allowed the honor of advancing to the great square, and hoisting the American flag on the National Palace. At 9 o'clock the Commander-in-Chief, attended by his brilliant staff, rode into the vast area in front of the venerable Cathedral and Palace, amid the shouts of the exulting army to whose triumphs his prudence and genius had so greatly contributed. It was a proud moment for Scott, and he might well have flushed with excitement as he ascended the Palace stairs and sat down in the saloon which had been occupied by so many Viceroys, Ministers, Presidents and Generals, to write the brief order announcing his occupation of the capital of Mexico. Yet the elation was but momentary. The cares of conquest were now exchanged for those of preservation. He was allowed no interval of repose from anxiety. His last victories had entirely disorganized the Republic. There was no longer a national government, a competent municipal authority, or even a police force which could be relied on to regulate the fallen city. Having accomplished the work of destruction, the responsibility of reconstruction was now imposed upon him; and first among his duties was the task of providing for the safety and subordination of that slender band which had been so suddenly forced into a vast and turbulent capital.