USA HISTORY

Detailed explanation-1: -US President James K. Polk (1845-1849) is the leader most associated with Manifest Destiny.

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: -James Polk as President 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.

Detailed explanation-4: -On May 12, 1846, the United States Senate voted 40 to 2 to go to war with Mexico. President James K. Polk had accused Mexican troops of having attacked Americans on U.S. soil, north of the Rio Grande.