Answer:
Following the American-Mexican War, a large party of Mexico was seceded to the United States by the Treaty of Guadalupe Hidalgo. Now, arises the question of slavery to extend in the newly acquired territory has torn the nation apart at-least politically. Some people questioned the morality of war as they believed that it was an attempt by the slave states to increase their domain. While Whigs were favoring Zachary Taylor, democrats were inclined towards General Cass who was a strong believer of popular sovereignty.