History Buffs: why did all southerns support slavery?
The reason that most Southern Whites supported slavery in the prewar south is really one of class and not race. No matter how dirt poor or uneducated a white man was, even the day laborers who worked side by side with slaves in the fields, a white man was still better than a black man. Its called the Southern Aristocracy. Southern society was divided into many different classes. There were the rich land owners, the merchant class, the small farmers, the lower classes, and then the slaves. When the Civil War started many of the poor whites enlisted to protect that social class system. They saw the Abolitionists as a threat to their daily life and their right to live as they saw fit. Read Eric Foner's works for a more detailed answer.
What was an incident from Martin Van Buren's term where he made an important decision?
Van Buren oversaw the Cherokee expulsion. He sided with the Spanish in the Armistad case. In 1839, Joseph Smith, Jr., the founder of the Latter Day Saint movement visited Van Buren to plead for the U.S. to help roughly 40,000 Mormon settlers of Independence, Missouri, who had been attacked, killed, raped, and run out of the state from their lands The Governor of Missouri, Lilburn Boggs, had issued an "Extermination Order". It authorized Missourians to "exterminate" Mormons and encouraged them to do so. Smith and his party begged Van Buren to intercede for the Mormons. He reportedly told Smith, "Your cause is just, but I can do nothing for you. If I take up for you I shall lose the vote of Missouri. Had he decided differently in any of these cases, he might have made pollitcal enemies, but he would have created a climate of tolerance that would have changed the moral character of the country. Had he done so the riights of minority citizens would have been recognized a hundred years before the civil rights movement. Because his and Jacksons policies lead to moral and financial collapse, Van Buren only served one term in office, any way.