The territory in dispute included the Mesilla valley. Bordering the Rio Grande, the valley consisted of flat desert terrain measuring approximately 50 miles, from north to south, for 200 miles, from east to west. This valley was essential for the construction of a transcontinental railroad using a southern route. The region purchased between the United States government and Mexico is known as Gadsden Purchase.
<span>This led to the Gadsden Purchase, so choice (c) is the correct answer. The Mesilla Valley was claimed by both Mexico and the US, and eventually was purchased by the Minister to Mexico as a way of defusing the conflicts between the governor of New Mexico and the sitting Mexican president.</span>
