The American forces, as we have stated, had concentrated at Puebla on the main road to the city of Mexico, but their numbers had been thinned by desertion, disease and the return of many volunteers whose term of service was over or nearly completed. Meanwhile the Mexican army was increased by the arrival of General Valencia from San Luis with five thousand troops and thirty-six pieces of artillery, and General Alvarez with his Pinto Indians from the south and south-west, all of which, added to the regiments in the city and its immediate vicinity, swelled the numbers of the Mexican combatants to at least twenty-five or thirty thousand. It was discovered that General Taylor would not advance towards the south, and consequently the presence of Valencia's men was of more importance at the point where the vital blow would probably be struck.

Whilst the events we have related were occurring in the interior, Commodore Perry had swept down the coast and captured Tobasco, which, however, owing to its unhealthiness, was not long retained by the Americans. But every other important port in the Gulf, from the Rio Grande to Yucatan, was in our possession, while an active blockade was maintained before those in the Pacific. Colonel Bankhead subsequently, occupied Orizaba, and seized a large quantity of valuable public property. It had been the desire of the American authorities, from the earliest period of the war, to draw a large portion of the means for its support from Mexico, but the commanding Generals finding the system not only annoying to themselves but exasperating to the people and difficult of accomplishment, refrained from the exercise of a right which invaders have generally used in other countries. Our officers, accordingly, paid for the supplies obtained from the natives. Nor did they confine this principle of action to the operations of the military authorities alone whilst acting for the army at large, but, wherever it was possible, restrained that spirit of private plunder and destruction which too commonly characterizes the common soldier when flushed with victory over a weak but opulent foe. When the ports of Mexico, however, had fallen into our possession and the blockade was raised, they were at once opened to the trade of all nations upon the payment of duties more moderate than those which had been collected by Mexico. The revenue, thus levied in the form of a military contribution from Mexican citizens upon articles they consumed, was devoted to the use of our army and navy. It was, in effect, the seizure of Mexican commercial duties and their application to our necessary purposes, and thus far, only, was the nation compelled to contribute towards the expense of the war it had provoked.

*****

Early in August, General Scott had been reinforced by the arrival of new regiments at Puebla, and on the 7th of that month, he resolved to march upon the capital. Leaving a competent garrison in that city, under the command of Colonel Childs, and a large number of sick and enfeebled men in the hospitals, he departed with about ten thousand eager soldiers towards the renowned Valley of Mexico.

In the same month, three hundred and twenty-eight years before, Hernando CortÉz and his slender military train, departed from the eastern coasts of Mexico, on the splendid errand of Indian conquest. After fighting two battles, with the Tlascalans who then dwelt in the neighborhood of Puebla, and with the Cholulans whose solitary pyramid,—a grand and solemn monument of the past,—still rises majestically from the beautiful plain, he slowly toiled across the steeps of the grand volcanic sierra which divides the valleys and hems in the plain of Mexico. Patiently winding up its wooded sides and passing the forests of its summit, the same grand panoramic scene lay spread out in sunshine at the feet of the American General that three centuries before had greeted the eager and longing eyes of the greatest Castilian soldier who ever trod the shores of America.

In order to comprehend the military movements which ended the drama of the Mexican war, it will be necessary for us to describe the topography of the valley with some minuteness, although it is not designed to recount, in detail, all the events and personal heroism of the battles that ensued. This would require infinitely more room than we can afford, and we are, accordingly, spared the discussion of many circumstances which concern the merits, the opinions, and the acts of various commanders.

*****

Looking downward towards the west from the shoulders of the lofty elevations which border the feet of the volcano of Popocatepetl, the spectator beholds a remarkable and perfect basin, enclosed on every side by mountains whose height varies from two hundred to ten thousand feet from its bottom. The form of this basin may be considered nearly circular, the diameter being about fifty miles. As the eye descends to the levels below, it beholds every variety of scenery. Ten extinct volcanoes rear their ancient cones and craters in the southern part of the valley, multitudes of lesser hills and elevations break the evenness of the plain, while, interspersed among its eight hundred and thirty square miles of arable land and along the shores of its six lakes of Chalco, Xochimilco, Tezcoco, San Cristoval, Xaltocan and Zumpango, stretching across the valley from north to south, are seen the white walls of ten populous cities and towns. In front of the observer, about forty miles to the west, is the capital of the Republic, while the main road thither descends rapidly from the last mountain slopes, at the Venta de Cordova, until it is lost in the plain on the margin of Lake Chalco near the Hacienda of Buena Vista. From thence to the town of Ayotla it sweeps along the plain between a moderate elevation on the north and the lake of Chalco on the south.

On the 11th of August, General Scott, after crossing the mountains, concentrated his forces in the valley. General Twiggs encamped with his division in advance, on the direct road, at Ayotla, near the northern shore of Lake Chalco; General Quitman was stationed with his troops a short distance in the rear; General Worth occupied the town of Chalco on the western shore of its lake, while General Pillow brought up the rear by an encampment near Worth.

This position of the army commanded four routes to the capital whose capture was the coveted prize. The first of these, as well as the shortest and most direct, was the main post road which reaches the city by the gate or garita of San Lazaro on the east. After passing Ayotla this road winds round the foot of an extinct volcanic hill for five miles when it approaches the sedgy shores and marshes of Lake Tezcoco on the north, thence it passes over a causeway built across an arm of Tezcoco for two miles, and, by another causeway of seven miles finally strikes the city. The road is good, level, perfectly open and comfortable for ordinary travelling, but the narrow land between the lakes of Chalco and Tezcoco, compressed still more by broken hills and rocks, admits the most perfect military defence. At the end of the first causeway over the arm of Tezcoco which we have just described, is the abrupt oblong volcanic hill styled El PeÑon, four hundred and fifty feet above the level of the lake, its top accessible in the direction of Ayotla at only one point, and surrounded by water except on the west towards Mexico. It is a natural fortress; yet Santa Anna had not neglected to add to its original strength, and to seize it as the eastern key of his defences. Three lines of works were thrown up, at the base, at the brow, and on the summit of the eminence. The works at the base, completely encircling El PeÑon, consisted of a ditch fifteen feet wide, four and a half feet deep, and a parapet fifteen feet thick whose slope was raised eight and a half feet above the bottom of the ditch. Ample breastworks formed the other two lines of the bristling tiara. In addition to this, the causeway across the arm of Tezcoco, immediately in front, had been cut and was defended by a battery of two guns, while the fire from all the works, mounting about sixty pieces, swept the whole length of the causeway.

The second road to the capital was by Mexicalzingo. After leaving Ayotla the highway continues along the main post road for six or seven miles and then deflects southwardly towards the village of Santa Maria, whence it pursues its way westwardly towards Istapalapan, but, just before reaching Mexicalzingo, it crosses a marsh formed by the waters of Lake Xochimilco, on a causeway nearly a mile long. This approach, dangerous as it was by its natural impediments, was also protected by extensive field works which made it almost as perilous for assault as the PeÑon.

The third route lay through Tezcoco. Leaving Chalco and the Hacienda of Buena Vista, it strikes off from the main route directly north, and passing through the town of Tezcoco, it sweeps westwardly around the shores of the lake of that name until it crosses the stone dyke of San Cristoval, near the lake and town of that name; thence, by a road leading almost directly south for fifteen miles, through the sacred town of Guadalupe Hidalgo, it enters the capital. It is an agreeable route through a beautiful country, yet extremely circuitous though free from all natural or artificial obstacles, until it reaches Santiago Zacualco within two miles of Guadalupe. But at the period of Scott's invasion of the valley, General Valencia, with the troops that were afterwards convened at Contreras, was stationed at Tezcoco, either for the purpose of observation, or to induce an attack in that quarter, and thus to draw our forces into a snare on the northern route, or to fall on the rear of the American commander if he attacked El PeÑon, or advanced by the way of Mexicalzingo. At Santiago Zacualco, west of the lake and on the route, formidable works were thrown up to defend the entire space between the western shore of lake Tezcoco and the mountains; while on the road to QuerÉtaro, at the mountain pass north of Tenepantla, other defences were erected, so as to screen the country on all sides of the group of hills which lies west of the lakes of Tezcoco and San Cristoval and north of the town of Guadalupe Hidalgo.

The fourth and last advance to the city was that which turned to the south from the Hacienda of Buena Vista, and passing by the town of Chalco, led along the narrow land intervening between the shores of lake Chalco and the first steeps of the mountains forming the southern rim of the valley, until it fell at right angles, at Tlalpam or San Agustin de las Cuevas, into the main road from the city of Mexico towards the southern States of the Republic.

All these routes were boldly reconnoitred by the brave engineers accompanying the American army, and, where they could not extend their personal observations, the officers obtained from the people of the country, information upon which subsequent events proved that they were justified in relying. From the knowledge thus gained as to the route south of the lake of Chalco, they were induced to believe, although it was rough, untravelled, difficult, and narrowly hemmed in between the lake and the mountains, yet that the long and narrow defile, which was open to resistance at many points, was not sufficiently obstructed or fortified to prevent our passage. All the routes on the lower lands, it should also be remembered, were liable to increased difficulties from the deluging rains prevailing at this season on the highlands of Mexico, and which sometimes convert the highways and their borders, for many leagues, into almost impassable lagunes.

Santa Anna and his engineers had probably supposed that this southern route would not be adopted, but a reasonable explanation of his conduct is given by one of the most competent commentators upon the valley of Mexico and the march of the American army. [69] "When an enemy is in front of El PeÑon, the communication between it and troops on the other routes is only by way of the city of Mexico itself; in other words, the American troops being at Ayotla, General Santa Anna's forces at El PeÑon were one day's march distant from those at Mexicalzingo, three from those under General Valencia, and would have been about four days' march from troops thrown forward on the Chalco route. Fords on these different routes were by no means within supporting distances of each other. Holding the position that General Scott then did, it would have required, of an equal enemy, four times his own force, to have opposed successfully his further advance. The Mexican forces were not numerically equal to this, and, accordingly, they were concentrated at the threatened point. It is evident that as long as the American troops were in front of El PeÑon, the enemy necessarily held to their position. In moving off, the former could gain one day the start. This brought the only difficult parts of the Chalco route actually nearer General Scott than the Mexican chief. If to this we add the delay necessary in moving heavy artillery and breaking up from a fortified position, it would seem that, instead of oversight, it was rather impossible for General Santa Anna to meet our forces sooner than he did."

The description of the various routes to the capital has necessarily acquainted the reader with the important Mexican defences on the north, the east, and the north-east of the capital, both by military works hastily thrown up after Santa Anna's retreat from Cerro Gordo, and by the encampment of large bodies of soldiery. We thus, already know a part of the external line of defences at El PeÑon, Mexicalzingo, Tezcoco, Santiago Zacualco, and the Pass north of Tenepantla. But in addition to these, there are others that must be noticed on the south and west of the capital, which it should always be recollected is situated in the lap of the valley, but near the western edge of the gigantic rim of mountains.

Along the Chalco route there were no more fortifications, but west of lakes Chalco and Xochimilco, a line of entrenchments had been commenced, connecting the fortified hacienda, or massive stone plantation house of San Antonio, about six miles south of the city, with the town of Mexicalzingo. West of this hacienda, the Pedregal, a vast, broken field of lava, spread out along the edge of the main road, and skirting it to San Agustin, extended high upon the mountain slopes still further west near San Angel and Contreras, whose neighboring fields were cut into deep ravines and barrancas by the wash from the declivities. The Pedregal was a most formidable obstacle in the march or manoeuvres of an army. But few levels of arable land were found among its rocky wastes. It admitted the passage of troops at but few points, and was entirely impracticable for cavalry or artillery, except by a single mule-path. [70] North of San Angel and the edge of the Pedregal, at the distance of about four miles, rose the solitary hill and castle of Chapultepec, which had been amply prepared for defence; and still further north on the same line, frowned the stern ridges of the sierra, cut by barrancas and profound dells, until the ring of the outer series of military works was thus finally united at the pass beyond Tenepantla. But inside of this formidable barrier of outworks, nearer the city, another line of fortifications had been prepared to dispute the American march. The first, and perhaps the most important of these, was at Churubusco, a scattered village lying midway between San Agustin and the city of Mexico, directly on the road, at a spot where the stream or rivulet of Churubusco runs eastwardly from a point on the road from San Angel to the capital, towards the lake of Xochimilco. The sides of the water course were planted with the prickly maguey, and one of the most western buildings in the village was a strong massive stone convent, whose walls had been cut for musketry, and whose parapets, azotÉas or flat roofs, and windows, all afforded suitable positions for soldiery. Large quantities of ammunition were stored within the edifice. The enclosure of the church and convent was defended by about two thousand men, and mounted seven guns, while, towards the east was a beautiful, solid and scientifically constructed tÊte de pont which covered the bridge over the stream by which the road led to the capital. In this work three heavy guns were mounted, while the neighborhood is said to have swarmed with troops.

We have already mentioned the garita or gate of San Lazaro, which was the entrance to the city by the main road from the east, passing the hill and fortification of El PeÑon. This garita was strengthened by strong works on the road, with platforms and embrasures for heavy cannon, which would have swept the path, while the marshes on the south were protected by redoubts and lunettes extending to the garita or entrance of La Candelaria on the canal from Xochimilco. North of San Lazaro strong works hemmed in the city to the garita of Peralvillo, and connected with defences and fortified houses reaching to the garita of Santiago. Other advanced works were begun in that quarter, while the ground in front of the main line was cut into troux de loups.

On the west of the city are the garitas of San CosmÉ and Belen. "Works had been commenced to connect that of San CosmÉ, the most northerly of the two, with that of Santiago, and the nature of the country and of the buildings, formed obstructions to any advance between San CosmÉ and Belen. Belen was defended principally by the citadel of Mexico, a square bastioned work with wet ditches, immediately inside the garita. Barricades had also been commenced; but the great obstacle to an entrance by either garita, was presented in the rock and castle of Chapultepec, two miles south-west of the city. From this hill two aqueducts extend to the capital, the one, north-east, in a direct line to Belen, and the other, north, to the suburb of San CosmÉ, where, turning at right angles, it continued onward and entered at the garita. The roads from the west ran along the sides of the aqueducts. Two roads enter the city from the south, between the garita of San Antonio and Belen, one at Belen and the other at the garita of El niÑo Perdido, neither of these roads have branches to the Acapulco road south of the Pedregal and the Hacienda of San Antonio, and, therefore, had been left comparatively unfortified." [71]

These defences, overlooked by the lofty sierras and the barrancas which broke their feet, hemmed in the capital, and the Mexicans readily imagined that they could not be turned by an army marching from the east, so as to reach the city on the west, except by a tedious circuit which would allow them time to complete their protective works in that quarter. The east had claimed their chief and most natural attention, and thus the south and the west became unquestionably their weakest points.

*****

Such were the Mexican lines, natural and artificial, around the capital in the valley in the middle of August, 1847, and such was the position of the American troops in front of them. The Mexicans numbered then, with all their levies, probably more than thirty thousand fighting men, while the Americans did not count more than ten thousand—under arms at all points. The invaders had prepared as well as circumstances admitted, and their materiel for assault or siege had been gathered carefully, and transported slowly into the interior, through the country intervening between Vera Cruz and Puebla, every train being usually attacked by guerillas, and fighting its way boldly through the most dangerous passes.

The equipments of the Mexicans, except the weapons saved from the wreck of former battles, had been chiefly prepared at the cannon foundries and powder factories of the country, and it is quite amazing to notice how completely a great exigency brought forth the latent energies of the people, teaching them what they might ordinarily effect, if guided by a spirit of industry and progress. Under the most disheartening depression, but fired by the stimulus of despair, by an overpowering sense of patriotic duty, and by religious enthusiasm which had been excited by the crusading address of the clergy of San Luis Potosi, issued in the month of April, they manifested in their last moments, a degree of zeal, calmness, and foresight that will forever redound to their credit on the page of history.

*****

The Mexican preparations for defence were not, of course, as completely known to the Americans as we now describe them. Through spies, scouts and reconnoisances of our engineers, some of the exterior, and even of the interior lines were ascertained with tolerable accuracy; but sufficient was known to satisfy General Scott that of all the approaching routes to the capital, that which led along the southern shores of lake Chalco was the only one he ought to adopt. [72]

Accordingly, on the 15th of August, the movement was commenced in the reverse order from that in which the army had entered the valley from Puebla. Worth's division passing Pillow's, led the advance, Pillow and Quitman followed, while Twiggs' brought up the rear. Scott took his position with Pillow, so as to communicate easily with all parts of the army. Water transportation, to some extent, had been obtained by General Worth at Chalco, by the siezure of market boats which plied between that place and the capital. When Twiggs moved he was assailed by Alvarez and his Pintos, but soon drove them off, while the advance columns, after passing San Gregorio, were frequently assailed by the enemy's light troops in their front, and harassed and impeded by ditches that had been hastily cut across the road, or by rocks rolled down from the mountains. These obstacles necessarily consumed time, but the simple-minded Indians of the neighborhood, who had just been compelled by the Mexicans to throw the impediments in the Americans' way, were perhaps more easily induced to aid in clearing the path for the invaders, than their ancestors had been in the days of CortÉz. On the afternoon of the 17th, Worth, with the advance, reached San Agustin, at the foot of the mountains, and at the intersection of the southern road from Mexico to Cuernavaca and Acapulco—a point whose topography we have already described;—and, on the 18th, the rear division entered the town.

As soon as Santa Anna discovered Scott's advance by the Chalco route, and that the attack on Mexico would be made from the south instead of the east, he at once perceived that it was useless to attack the American rear, whilst passing the defiles between the lake and the mountains even if he could possibly come up with it, and consequently, that it was best for him to quit his head quarters at El PeÑon, while he also recalled General Valencia with the most of the troops at Tezcoco and at Mexicalzingo, which were no longer menaced by the foe. Santa Anna himself, established his quarters at the fortified hacienda of San Antonio, and ordered Valencia to march his whole division, cavalry, infantry and artillery, to the town of San Angel and Coyoacan, so as to cover the whole west and centre of the valley in front of Mexico.

[69] See the admirable Map and Memoir of Lieutenant M. L. Smith, and Brevet Captain E. L. F. Hardcastle, published in the Senate Document, No. 11 of the first session of the 31st Congress: 1849 '50. [70] Ripley's War with Mexico, vol. 2, 181. [71] Ripley, 2d vol., 182. [72] General Scott had set his heart, even at Puebla, on the Chalco route, but he resolved not to be obstinate, if, on a closer examination of the ground, a better route was presented. The last information of his spies and officers, in the valley, satisfied him as to the propriety of advancing by Chalco.