11.) James K. Polk 1845-1849

No president better captures the spirit of Manifest Destiny than James K. Polk. When he entered office, the United States had a disputed claim to Oregon, and that's about it. When he left office, the United States looked like the continent-spanning empire it is today.. Follow along as Polk revives his dead-end political career to shock everyone and win the White House, manipulates the United States into war with Mexico to steal the American Southwest, acquires the Oregon Territory from Great...