Describe three reasons why many Americans believed it was the US's "manifest destiny" to expand the nation to the Pacific Ocean.

1. The US needed room for American population growth. The newspaper article that coined the term "manifest destiny" stated that westward expansion to the Pacific Ocean was a practical necessity to continue "the free development" (under American representative government) of our "yearly multiplying millions." The US population had grown dramatically from 5 million in 1800 to more than 23 million by 1850.
2. Americans believed in divine providence. The idea that Americans were a divinely chosen people of destiny goes all the way back to John Winthrop's "Shining City on a Hill" sermon. Early Americans viewed the vast, sparsely settled continent as a sign of God's providential blessing for them.
3. Americans desired national security. Sophisticated observers noted that being hemmed in by any foreign power (like Great Britain) to the west would pose unacceptable security risks for the United States. Security of the republic required holding the number of our borders to the absolute minimum of Canada and Mexico. The Pacific would provide greater security than any western neighbor.