Documents: Westward Expansion
In 1848, the United States and Mexico signed the Treaty of Guadalupe Hidalgo ending the Mexican American War. In the treaty, the Mexican government gave the United States the following: California and the province of New Mexico known as the Mexican Cession; set the Rio Grande River as the southern border of the United States; and in return the U.S. paid the Mexican government $15 million for the land. The Mexican Cession eventually was carved up into several states that included present-day Arizona, New Mexico, and parts of Utah, Nevada, and Colorado. This treaty helped the United States fulfill its Manifest Destiny goal.