Final answer:
Manifest Destiny was a concept that emerged in the 1840s and justified American expansion across the continental United States. It expressed the belief that the United States had a divine mission to spread democratic institutions and take political and economic control of the continent.
Step-by-step explanation:
Manifest Destiny was a concept that emerged in the 1840s and justified American expansion across the continental United States. It expressed the belief that the United States had a divine mission to spread democratic institutions and take political and economic control of the continent. This expansion led to the acquisition of territories such as Texas, Oregon, and California, and it was seen as inevitable and justified by the idea of a divine destiny.