Pedregal - Santa Anna at Bay

After capturing Vera Cruz and routing Santa Anna at Cerro Gordo in the spring, Winfield Scott’s US Army was poised to strike at Mexico City. Boldly cutting himself loose from his supply line—as Cortes had done three centuries earlier—Scott embarked upon a risky campaign: He had only slender political support; a single reverse—or an inordinately bloody victory—might have spelled the end of his campaign. Instead of an assault on Mexican fortifications east of the capital, Scott circled to the south where large lakes and a lava bed (the Pedregal) gave him numerous approach routes. The Mexicans quickly moved to block him, fortifying the most obvious routes, but they neglected to man the Pedregal itself, thinking it impassable to large units. The US forces, led by an excellent set of engineer officers, repeatedly found paths through the morass. But the US army was roughly half the size of the Mexican army and necessarily was divided. A resolute Mexican attack at the proper moment could have led to the destruction of Scott’s army.