How was The annexation of Texas and the Mexican cession best described as efforts by the US to?

The annexation of Texas and the Mexican Cession can be best described as efforts by the U.S. to expand its territory and fulfill the doctrine of Manifest Destiny, which held that Americans were destined to expand across the continent. This expansionist mindset was motivated by a desire for land, resources, and economic opportunities. The annexation of Texas in 1845 and the subsequent acquisition of territories following the Mexican-American War in 1848 significantly increased U.S. land holdings and played a crucial role in shaping the nation's borders.