Discuss the American rationale for going to war with Mexico in 1846. In your response, please examine the roles Manifest Destiny and the expansion of slavery may have played in President James Polk's decision to ask Congress for a declaration of war.

The Mexican-American War was an military conflict between Mexico and the USA caused by the latter's occupation of the state of Texas. The fighting had to do with America's strong feelings of nationalism justified by Manifest Destiny, which was the belief that the country was destined by God to expand  its territory. Besides, the south needed more southern states to spread out slavery, since it was forbidden in the northern states. Thus, because the Mexican government refused to sell the state of Texas, the US president James K. Polk decided to declare war on Mexico.

religion played a major role in the american revolution by offering a moral sanction for opposition to the british--an assurance to the average american that revolution was justified in the sight of god. the revolution strengthened millennialist strains in american.