Final answer:
Manifest Destiny was the belief that Americans were destined to expand their influence across North America, which involved land acquisition and the Americanization of indigenous populations.
Step-by-step explanation:
Manifest Destiny was a concept associated with the expansion of the United States in the 1840s. It referred to the belief that it was the destiny of Americans to spread their democratic institutions and control the entire continent of North America. This expansion not only involved the acquisition of land but also the Americanization of the indigenous populations. The settlers' descriptions of American expansion often included the idea that it was a divine mission and that any resistance to this expansion would be forcibly extinguished.