<P> The Gadsden Purchase ( known in Mexico as Spanish : Venta de La Mesilla , `` Sale of La Mesilla '' ) is a 29,670 - square - mile ( 76,800 km ) region of present - day southern Arizona and southwestern New Mexico that the United States purchased via a treaty signed on December 30 , 1853 , by James Gadsden , U.S. ambassador to Mexico at that time . The U.S. Senate voted in favor of ratifying it with amendments on April 25 , 1854 , and then transmitted it to 14th President Franklin Pierce . Mexico 's government and its General Congress or Congress of the Union took final approval action on June 8 , 1854 . The purchase was the last substantial territorial acquisition in the contiguous United States . The U.S. sought the land as a better route for the construction of the southern transcontinental railway line , and the financially - strapped government of Antonio López de Santa Anna agreed to the sale , which netted Mexico $10 million ( equivalent to $270 million in 2017 ) . After the devastating loss of Mexican territory to the U.S. in the Mexican -- American War ( 1846 -- 48 ) and the continued filibustering by U.S. citizens , Santa Anna may have calculated it was better to yield territory by treaty and receive payment rather than have the territory simply seized by the U.S. </P>
<P> The Gadsden Purchase ( known in Mexico as Spanish : Venta de La Mesilla , `` Sale of La Mesilla '' ) is a 29,670 - square - mile ( 76,800 km ) region of present - day southern Arizona and southwestern New Mexico that the United States purchased via a treaty signed on December 30 , 1853 , by James Gadsden , U.S. ambassador to Mexico at that time . The U.S. Senate voted in favor of ratifying it with amendments on April 25 , 1854 , and then transmitted it to 14th President Franklin Pierce . Mexico 's government and its General Congress or Congress of the Union took final approval action on June 8 , 1854 . The purchase was the last substantial territorial acquisition in the contiguous United States . The U.S. sought the land as a better route for the construction of the southern transcontinental railway line , and the financially - strapped government of Antonio López de Santa Anna agreed to the sale , which netted Mexico $10 million ( equivalent to $270 million in 2017 ) . After the devastating loss of Mexican territory to the U.S. in the Mexican -- American War ( 1846 -- 48 ) and the continued filibustering by U.S. citizens , Santa Anna may have calculated it was better to yield territory by treaty and receive payment rather than have the territory simply seized by the U.S. </P>
who did we buy the gadsden purchase from
who did we buy the gadsden purchase from
Mexico
Mexico