- a tract of 45,535 sq. mi. (117,935 sq. km), now contained in New Mexico and Arizona, purchased for $10,000,000 from Mexico in 1853, the treaty being negotiated by James Gadsden.
- an area of about 77 000 sq km (30 000 sq miles) in present-day Arizona and New Mexico, bought by the US from Mexico for 10 million dollars in 1853. The purchase was negotiated by James Gadsden (1788–1858), US diplomat