In terms of accomplishments, James’s Polk one-term record is hard to beat. His first three feats alone – the adjustment to the tariff, the establishment of the Constitutional Treasury, and the resolution of the Oregon boundary dispute with Britain – each resolved decades of conflict, some of which were in the realm of the most intense in the nation’s history. If Polk is known for anything, however, it was the decisive victory in the war with Mexico and the vast expanse of land that devolved to the United States via the Mexican Cession. Polk gave life to the concept of Manifest Destiny, embracing the expansionist vision, putting the strategy into place, and overseeing its successful, albeit bloody, conclusion. The Mexican War was not universally embraced by the American populace, and the President’s role in starting the conflict has appropriately been derided as disingenuous, at best. The entire venture was imperialistic in its aims and its execution, President Polk’s objections notwithstanding. … It also helped ensure a path to a fractured nation, as the slavery expansion issue could no longer be contained with all this new land at the nation’s disposal. James Polk’s impact is undeniable, but it’s a mixed tale in terms of the methods he used to achieve his objectives and the unintended consequences that helped lead his nation into Civil War.