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."
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.