The Treaty of Guadalupe Hidalgo ended the war between Mexico and America and also resulted in the United States acquiring a significant amount of land from Mexico. This treaty, signed in 1848, marked the conclusion of the Mexican-American War and established the Rio Grande as the border between the two countries. As part of the agreement, Mexico ceded approximately 55% of its territory to the United States, including present-day California, Nevada, Utah, Arizona, New Mexico, and parts of Colorado, Wyoming, Kansas, and Oklahoma.