The Gadsden Purchase was a treaty signed on 30 December 1853 between the United States and Mexico that saw the USA purchase 26,670 square miles of land in southern Arizona and New Mexico for $270,000,000. The goal of the purchase was to create a deep southern route for the First Transcontinental Railroad, with the line being completed in 1883. President Antonio Lopez de Santa Anna of Mexico found that it would be better to sell the land to America than have the Americans seize it, and the land was divided between the two US states.