The Mexican-American War officially ended with the Treaty of Guadalupe. In this treaty, the U.S. kept the Texas territory. The U.S. also gained California, Nevada, New Mexico, and parts of Arizonia and Utah. In exchange for the land, the U.S. paid Mexico $15 million dollars. This compromise was perfectly successful for the U.S. The nation gained exactly what it had set out to get by starting the war. Mexico lost approximately 55 percent of its territory. The treaty stated that all Mexicans living in the area now owned by the U.S. would be given automatic U.S. citizenship.
To learn more about the Mexican views on the treaty, click on Mexican perspective.