Following the fall of Mexico City, the Mexican government was in turmoil. Polk had authorized payment of $30 million for New Mexico, upper and lower California, and the right of transit across Mexico’s narrow isthmus of Tehuantepec. Now, observing the disorganized state of Mexican affairs, he began to consider demanding more territory and Paying less for it. He recalled his chief negotiator, Nicholas P. Trist, who ignored the order. Trist realized that unless a treaty was arranged soon, the Mexican government might disintegrate, leaving no one in authority to sign a treaty. He dashed off a sixty-five-page letter to the president, in effect refusing to be recalled, and continued to negotiate. Early in February the Treaty of Guadalupe Hidalgo was completed. By its terms Mexico accepted the Rio Grande as the boundary of Texas and ceded New Mexico and upper California to the United States. In return the United States agreed to pay Mexico $15 million and to take on the claims of American citizens against Mexico, which by that time amounted to another $3.25 million.
When he learned that Trist had ignored his orders, the president ordered that he be fired from the State Department and placed under arrest. Yet Polk had no choice but to submit the treaty to the Senate, for to have insisted on more territory would have meant more fighting, and the war had become increasingly unpopular. The relatively easy military victory made some people ashamed that their country was crushing a weaker neighbor. Abolitionists, led by William Lloyd Garrison, called it an “invasion. . . waged solely for the detestable and horrible purpose of extending and perpetuating American slavery.” The Senate, subject to the same pressures as the president, ratified the agreement by a vote of thirty-eight to fourteen.
World History
