Manifest destiny was the 19th century belief that American settlers were destined to expand across North America from the Atlantic to the Pacific coast. It promoted the idea that it was both God's will and America's destiny to expand westward, and justified the removal of Native Americans from lands being settled. Examples of manifest destiny in action included the Louisiana Purchase, the war with Mexico, and the Indian removal policies like the Trail of Tears, while the Monroe Doctrine discouraged European intervention in the Americas.