Answer:
MANIFEST DESTINY
Step-by-step explanation:
It was a widely held belief in the 19th century that the expansion of the United States across the North American continent was not only inevitable but also justified and necessary for the country's survival and prosperity. Manifest Destiny was used as a justification for the United States' territorial expansion, including the annexation of Texas, the Mexican War, and the acquisition of California, Arizona, New Mexico, Nevada, and Utah from Mexico.