After falling to the United States in Mexico City in September 1847, the Mexican government surrendered to the United States and began negotiations to end the war. The result was the Treaty of Guadalupe Hidalgo. This document brought the U.S. – Mexican war to an official end. It was signed on February 2, 1848, at Guadalupe Hidalgo. The Mexican government had fled to this city as the U.S. troops advanced through Mexico.

Peace negotiations had initially been attempted with President Santa Anna but were unsuccessful. Nicholas Trist, chief clerk of the State Department, along with General Winfield Scott, represented President Polk in the final negotiations.

Source: Treaty of Guadalupe Hidalgo, Our Documents

Article V in the Treaty of Guadalupe Hidalgo set the new boundaries between the United States and Mexico. Mexico was reduced to half of its territorial size.

To read the full transcript of the Treaty of Guadalupe Hidalgo, click here: Treaty of Guadalupe Hidalgo

The map below illustrates the new boundaries of the United States after ratification of the Treaty of Guadalupe Hidalgo. Click on the two areas of the Mexican cession on the map below to learn more.

Answer the following questions in your notes.

1. In addition to extending its boundaries to the Pacific Coast, how else might the acquisition of this territory benefit the United States?
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The acquisition of this territory may benefit the United States by expanding its territory into neighboring Mexico. Also, the United States would increase in size, allowing more states to eventually be added.

2. The extension of the United States's boundaries caused concerns that it may also extend slavery into the west. How might these concerns affect the people of the United States?
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Americans were split over the issue of slavery. Those who opposed slavery were concerned that newly admitted states would become slave states, thus expanding the legislative power of slave states.

3. As a result of losing several battles and territory, in what ways might Mexico be affected?
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The loss of territory makes Mexico a geographically smaller country with less political influence. The loss of battles may give the impression that Mexico is a weaker nation than its opponents.