American imperialism

Manifest destiny

Manifest destiny was the expansionist belief in the 19th-century United States that American settlers were destined to expand westward across North America, and that this belief was both obvious ("manifest") and certain ("destiny").

Territorial evolution of the United States

The United States of America was formed after thirteen British colonies in North America declared independence from the British Empire on July 4, 1776. In the Lee Resolution, passed by the Second Continental Congress two days prior, the colonies resolved that they were free and independent states.