The Mexican–American War Practice Test

Secondary-source excerpt: In assessing the Mexican-American War, a scholar argues that Manifest Destiny ideology encouraged many Americans to view continental expansion as both inevitable and virtuous. The author suggests this belief helped generate popular support for war even as some opponents warned it would worsen sectional tensions.

Which piece of evidence would best support the scholar’s claim about Manifest Destiny shaping support for the war?

Secondary-source excerpt: One scholar argues that the Mexican-American War intensified U.S. interest in a southern transcontinental route and helped set the stage for later boundary adjustments. The author notes that U.S. leaders sought land suitable for a railroad line across the Southwest.

Which later event most directly aligns with this consequence?