In the late fall of 1846, President Polk faced one of the most difficult decisions of his political career. In the first six months of the war, U.S. forces had secured the administration’s territorial objectives. Yet despite de Ampudia’s surrender at Monterrey and the U.S. seizure of New Mexico and California, Mexican leaders had shown no inclination to come to the bargaining table.
As a result, Polk favored a strategy that would escalate the war in order to bring it to a speedy conclusion. An aggressive strategy, however, involved a high degree of risk. An invasion from the north was quickly ruled out as impractical for logistical reasons, for it would require U.S. troops to traverse hundreds of miles of arid and desolate terrain, leaving supply lines dangerously overextended. But a strategy to open a new front in the south presented equally obvious drawbacks. Mexico’s largest port city, Vera Cruz, was a logical target, but yellow fever wreaked havoc on the coastal population in the hottest months of the year, making a long-term occupation of the city difficult. Ordering a campaign against the Mexican capital presented different challenges. An American force would encounter poor mountain roads well-suited to guerilla warfare, conditions in which superior U.S. artillery would be of little advantage. Moreover, an invading force in the south could expect much stiffer resistance from the civilian population than it had in the north, where opposition to the central government had weakened national allegiances. There were political challenges, too; any military reverses would almost certainly delay rather than hasten negotiations with the Mexican government.
Despite these risks, on November 17, 1846 Polk ordered that preparations be made to launch a seaborne invasion of Vera Cruz. The decision as to whether to proceed into the interior of Mexico would be made later, but the president had already made up his mind to authorize a march on the capital should Mexican leaders refuse to negotiate.
To undertake an invasion of southern Mexico, the administration turned, reluctantly, to Winfield Scott, a prominent Whig whose presidential ambitions were well known. Polk would have preferred Democratic senator Thomas Hart Benton lead the campaign, but when the Senate refused to authorize Benton’s commission, he had no choice but to turn the operation over to Scott.
