USA HISTORY

Detailed explanation-1: -US President James K. Polk (1845-1849) is the leader most associated with Manifest Destiny. Manifest Destiny inflamed sectional tensions over slavery, which ultimately led to the Civil War.

Detailed explanation-2: -Under Polk, Manifest Destiny was put into action with the annexation of the nominally independent Texas and the ceding from Mexico of parts of nine states.

Detailed explanation-3: -Polk eventually achieved all his goals. He was a champion of manifest destiny–the belief that the United States was fated to expand across the North American continent–and by the end of his four years in office, the nation extended, for the first time, from the Atlantic Ocean to the Pacific Ocean.