Gadsden Purchase Treaty as first negotiated, (in English and Spanish), December 30, 1853
The Gadsden Purchase is a roughly 30,000 square-mile region of present-day southern Arizona and southwestern New Mexico
that was acquired by the United States in a treaty signed by American ambassador to Mexico James Gadsden on December 30, 1853.
The treaty was ratified, with changes, by the U.S. Senate and signed by President Franklin Pierce with final approval by Mexico
on June 8, 1854. The purchase was the last major territorial acquisition in the contiguous United States.