Major land transaction between the United States and Mexico in 1854.
The Treaty of Guadalupe Hidalgo ended the Mexican-American War (1845-1848) and ceded vast western territory to the United States, but it left the precise boundary between the United States and Mexico vague. The area in dispute lay south of the Gila River and north of the current border. Hoping to settle the matter and at the same time secure the best route for a southern transcontinental railroad, President Franklin Pierce appointed James Gadsden, a railroad entrepreneur, as minister to Mexico and instructed him to negotiate the purchase of the disputed area.
Gadsden’s original mission also included negotiating the purchase of lower California, but his abrasive personality offended Mexican authorities to such an extent that the country’s president, Antonio Lopez de Santa Anna, refused to consider the sale of additional territory. Gadsden eventually reached a tentative agreement with the Mexican president, and the issue went before the U.S. Senate. After making some modifications and engaging in heated debate along North/ South sectional lines, the Senate narrowly approved the purchase. Under the agreement the United States received 30,000 square miles that would form the southern portion of New Mexico and Arizona. In return, Mexico received $10 million, and both countries agreed to rescind or assume any additional claims against each other.
Although the Gadsden Purchase added significant territory to the United States, it generated a great deal of controversy. Many Americans, particularly in the North, viewed the entire episode as a brazen attempt by Southern politicians to advance their own interests. Debates in the Senate over the purchase further aggravated sectional tensions within the United States, and the issue did little to improve U.S.Mexican relations. In Mexico the sale proved so unpopular that it helped topple Santa Anna’s government.
