How did the US acquire the area labeled number Mexico on the map?

The area labeled as Mexico on the map was acquired by the United States primarily through the Treaty of Guadalupe Hidalgo in 1848, which ended the Mexican-American War. As a result of the treaty, Mexico ceded a vast portion of its northern territories, including present-day California, Arizona, New Mexico, Nevada, Utah, and parts of Colorado and Wyoming, to the U.S. Additionally, the Gadsden Purchase in 1853 further expanded U.S. territory in the region.