What is the definition of Manifest Destiny

Manifest Destiny, meaning "obvious (or undeniable) fate" was a belief originally held by Democratic Republicans, specifically Warhawks during the presidency of James Madison, that stated the United States had a divinely-inspired mission to expand itself and its system of government to the western frontier.

In the 1840s the phrase was used by politicians and leaders to justify and promote territorial expansion across the North American continent by providing a sense of mission to citizens. In theory, one aspect of this desire was its principle to bring the ideals of democratic self-government to any peoples capable of it; in practice, however, this often meant excluding Native Americans and those with non-European ancestry. Another desire was the acquisition of new lands, since land could represent potential income, wealth, self-sufficiency, and freedom.