The Mexican–American War, also known in America as the Mexican War and in Mexico as the American intervention, was an armed conflict between the United States of America and Mexico from 1846 to 1848.
It could be said that this conflict was motivated in part by the Americans manifest destiny, which claimed that it was the United States' right to expand westward and conquer territories, as well as the wishes of some South Americans to gain more "slave states" in order to increase their political power.
At the end of this war in 1848, with the signing and ratification of the Treaty of Guadalupe-Hidalgo, Mexico had lost about one-third of its territory, including the present California, Utah, Nevada, Arizona and New Mexico.
