Zachary Taylor was a Mexican War hero called “Ol’ Rough and Ready” for his slovenly appearance. He was courted by both parties to run in 1848, the Whigs and Democrats eager to capitalize on the political popularity war heroes always bring to an election. Taylor chose the Whigs.
Because he wasn’t a politician (he had never vote, not even in his own election), Taylor sought to take a backseat in office. He agreed with the Whig Party’s emphasis on Congress over the Presidency and promised to not use his veto powers as President. The great issue, of course, was the escalating debate over the expansion of slavery. Taylor, personally pro-slavery, believed that Congress should decide it, not the President.
Despite being sympathetic to slavery, Taylor was also firmly a Unionist. As the tension over states’ rights and slavery intensified, threats of secession became more common. If the country was created as a union of the separate states, deciding to join together for the common good, some argued that states also had the right to decide to leave the country if they wanted. Taylor rejected this idea, threatening to hang people arguing for secession.
The Missouri Compromise of 1820 had calmed the argument over slavery for a while, but by 1849, tension was building. In that legislation, Congress prohibited slavery in the Louisiana Territory north of 36°30′ (except in the proposed state of Missouri). This settled the debate over which new states would be free and which would be slave.
But the Mexican Cession and the acquisition of the Oregon Territory renewed animosity between the north and south in Congress and also led to more threats of secession. The tension as addressed with the Compromise of 1850, a package of five bills designed to give the pro-slavery and anti-slavery factions enough of what they wanted to avoid civil war. The compromise was the baby of Whig Senator Henry Clay (of Kentucky) and was supported by Democrat Stephen Douglas (Illinois).
As a package of separate bills, the Compromise of 1850 was multi-faceted. It superseded the Missouri Compromise because the boundary established in it was not followed. For example, California, which extended north and south of 36°30′, was admitted to the Union as a free state. And the New Mexico–formerly part of Texas and mostly south of the border–and Utah Territories–north of it–were set to decide for themselves if they would have slavery, using the doctrine of popular sovereignty instead of being pre-determined by the Missouri Compromise.
Of much greater significance in the compromise was the inclusion of the Fugitive Slave Law. Because of the number of escaped slaves fleeing north on the Underground Railroad, supported by northern abolitionists who called for the immediate elimination of slavery, the south was desperate for something to shut it down. This act of Congress made it the legal responsibility of all Americans to report and help return runaway slaves. Northern resentment to the law was widespread, outraged that they should have to support the institution.
Orchestrating the compromise was difficult for Clay. It was opposed by abolitionists in the Whig party and by the most ardent pro-slavery Democrats. Taylor also disapproved of it. He threatened to go against his promise to not use his veto powers if Congress passed it.
Taylor never had to break his promise. Before he had to use his presidential veto, he suddenly died. Though foul play was suspected, historians believe that he died of cholera. His Vice-President–Millard Fillmore–would have to deal with it.