How does the U.S government use Manifest Destiny to make the country grow?

The notion of Manifest Destiny was created in the 1840's by an American journalist. It was the theory that the ultimate future of the United States was to control all of the lands from the Atlantic coast to the Pacific coast. The theory was built on the notion of American exceptionalism and Christian theology. Theologically, it was a strong belief that God wanted Americans to have this land because they were better suited to take care of it and prosper. The theory had a very strong following in the American government, whether because of actual Christian beliefs, or the political expedience in promoting it.

The idea of Manifest Destiny would drive the expansion of American territory in the second half of the Nineteenth Century. This would include the acquisition of Oregon Territory, California, and the annexation of Mexican lands in the Southwest. The concept of Manifest Destiny also fueled American imperial excursions in the Caribbean in the early Twentieth Century.