What effect did the Mexican-American War have on American expansion?

The Mexican-American War significantly accelerated the acquisition of new territories for the United States. Following the conflict, the Treaty of Guadalupe Hidalgo in 1848 resulted in the U.S. gaining a vast expanse of land, including present-day California, Arizona, New Mexico, Nevada, Utah, and parts of Colorado and Wyoming. This influx of territory not only expanded the nation's borders but also intensified the national debate over slavery and its expansion into new states, which was a major factor in the political landscape of the time.

The war exemplified the idea of Manifest Destiny, the belief that it was the United States' destiny to expand its territory across North America. As a result, the Mexican-American War is often viewed as a pivotal moment in U.S. history that laid the groundwork for further westward migration and exploration, encouraging settlers to move into and develop these newly acquired regions. This expansion played a crucial role in shaping the nation’s identity and future economic development.