Why had the USA become a continental power by 1890?

The Belief of "Manifest Destiny"

"Our national birth (and the Declaration of Independence) was the beginning of a new history, which separates us from the past and connects us only with the future. We are the nation of progress, of individual freedom, of universal enfranchisement. Our future history will be to establish on earth the moral dignity and salvation of man -- the undeniable truth and goodness of God. America has been chosen for this mission among all the nations of the world, which are shut out from the life-giving light of truth. Her high example shall put an end to the tyranny of kings, and carry the happy news of peace and good will to millions who now endure an existence hardly better than that of beasts of the field. Who, then, can doubt that our country is destined to be the great nation of the future?"

From the essay "The Great Nation of Futurity” by John O’Sullivan, 1839.

Americans believed that:

The age of Manifest Destiny

The age of manifest destiny is most commonly known as the period of territorial expansion of the United States

The era begins with the War of 1812 and ends with the acquisition of Alaska in 1867.

Continental Territorial Acquisitions of the USA (1803-1867)

How did the USA acquire their territories?


Military Power


Threats & Negotiation

How did the US government settle the Western regions of America?