The Gadsden Purchase was an agreement between the United States and Mexico finalized in 1853, in which the United States acquired a large portion of land in what is now southern Arizona and New Mexico. The purchase helped establish the modern southern border of the continental United States.
Background
Following the Mexican–American War (1846–1848), the United States gained vast western territories through the Treaty of Guadalupe Hidalgo. However, disputes over the southern border and interest in building a southern transcontinental railroad route led to further negotiations between the two countries.
At the time, tensions remained high between the United States and Mexico, and both governments sought a diplomatic resolution to outstanding territorial and financial issues.
Negotiation and agreement
The agreement was negotiated by James Gadsden, the U.S. Minister to Mexico, during the presidency of Franklin Pierce. Under the terms of the treaty, the United States agreed to pay Mexico $10 million in exchange for approximately 29,670 square miles (76,800 km²) of territory.
The treaty was ratified by the United States Senate in 1854 after modifications to the original proposal.
Territory acquired
The Gadsden Purchase included land that now forms:
- Southern Arizona
- Southern New Mexico
The acquisition allowed the United States to construct transportation routes through more favorable terrain than previously available.
Significance
The Gadsden Purchase was the final major territorial expansion of the contiguous United States. It:
- Established the present-day U.S.–Mexico border
- Facilitated railroad development
- Strengthened U.S. influence in the Southwest
However, the purchase also intensified national debates over the expansion of slavery in the United States, contributing to political tensions in the years leading up to the American Civil War.
Legacy
Today, the Gadsden Purchase is remembered as a key event in U.S. territorial history and an important step in shaping the modern geography of the American Southwest.