Why did Gadsden purchase southern desert land?

The Gadsden Purchase, finalized in 1854, was primarily aimed at facilitating the construction of a southern transcontinental railway. The land acquired through this purchase included areas of southern Arizona and New Mexico, which were viewed as essential for establishing a direct rail route to connect the southern states of the U.S. with California. This acquisition was driven by the belief that a railway through this region would enhance trade and improve transportation across the continent, thus supporting westward expansion and economic growth.

The other options do address important themes in U.S. history but do not directly capture the primary motivation behind the Gadsden Purchase. For example, while the idea of creating a buffer between Mexico and the U.S. was an ongoing concern, it was not the central reason for this specific land transaction. Similarly, preserving unique desert lands and providing living areas for Native Americans were important issues at the time but were not the main intentions behind the Gadsden Purchase. The emphasis on developing infrastructure, particularly the transcontinental railway, highlights the critical role of this land acquisition in shaping the transportation landscape of the United States.