Answer: Allowed for the Acquisition of the western territories
Explanation:
The Manifest Destiny was a belief that the United States was meant to exist from the east to the west of the North American continent which would enable them to bring development, democracy and capitalism across the continent.
The Mexican-American War of 1846 - 1848 allowed them to accomplish this as Mexico lost and was forced to sign a peace treaty that saw them lose 55% of their territory to the United States, which gained all or some of the present day territories of Arizona, California, New Mexico, Texas, Colorado, Nevada, and Utah.
This enabled the U.S. to extended from the East Coast to the West.
