Captain White has just given a succinct definition of Manifest Destiny, the 19th century American belief that the United States was destined to expand eastwards across the North American continent to the Pacific Ocean. The ideology was also used by Democrats in the 1840s to justify the war with Mexico.
The concept of American expansion is much older, but the phrase itself was coined by the influential journalist John L. O’Sullivan in 1845. The term would fall out of favour by the 1860s and by the turn of the 19th century to the 20th, territorial expansion ceased to be promoted as being part of America’s destiny. Instead, expansionism was replaced with interventionism, with America effectively positioning itself as an ‘international police power’.
Many critics of American foreign policy continue to use the phrase Manifest Destiny to characterise interventions in the Middle East and elsewhere, interpreting it as the underlying cause of what some describe as ‘American imperialism.’