The Avalon Project at Yale Law School provides a transcription of the Gadsden Purchase Treaty as amended by the Senate of the United States and signed by President Franklin Pierce on June 30, 1854. The version of the treaty which was signed in Mexico on December 30, 1853 specified that the United States would pay $15 million for 45,000 square miles of territory. However, when the U.S. Senate ratified the treaty on April 25, 1854, only $10 million was authorized for the purchase of 29,670 square miles of territory. The renegotiated treaty was signed by Antonio López de Santa Anna on June 8, 1854. See also: Gadsden Purchase, 1853-1854 (U.S. Department of State, Office of the Historian).