Purchase (known as Venta de La Mesilla, or Sale of La Mesilla,
in Mexico) is a 29,670
square-mile (76,800 km2) region of present-day southern Arizona and southwestern New Mexico
that was purchased by the United States in a treaty signed by James Gadsden,
the American ambassador to Mexico at the time, on December 30, 1853.
It was then ratified, with changes, by the U.S. Senate on April 25, 1854 and signed
by President Franklin Pierce, with final approval action taken by Mexico on June 8, 1854.
The purchase was the last major territorial acquisition
in the contiguous United States, adding a large area to the United States.
WIKIPEDIA HISTORY 19TH CENTURY