Final answer:
The United States made the Gadsden Purchase to create a buffer zone between Mexican and American interests and to facilitate the construction of the transcontinental railroad.
Step-by-step explanation:
The United States made the Gadsden Purchase to create a buffer zone between Mexican and American interests. In the mid-19th century, tensions between Mexico and the U.S. were high, especially after the Mexican-American War. The U.S. wanted to avoid future conflicts and secure its southern border, so it negotiated the purchase of a strip of land in present-day Arizona and New Mexico. The Gadsden Purchase also aimed to facilitate the building of a transcontinental railroad, which would connect the Atlantic and Pacific coasts and open up new trade routes.
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