In 1846, General Stephen Watts Kearny and about three hundred dragoon, of his "Army of the West" rode into Santa Fe to lay claim to New Mexico on behalf of the United States, a claim legalized two years later, in 1848, by the Treaty of Guadalupe Hidalgo. Along with it went most of what is now the southwestern United States, enlarged to its present boundaries through the ratification in 1854 of the Gadsden Purchase.