Millard Fillmore was sworn in as the 13th President of the United States on July 9, 1850, just one day after the death of President Zachary Taylor. Fillmore had been the Vice President under Taylor, having assumed that role after their elections in 1848. Taylor's presidency was marked by tensions surrounding the expansion of slavery into newly acquired territories, which became acute following the Mexican-American War. Fillmore's ascension to the presidency brought another dimension to these controversies, as he was seen as more favorable towards the compromises that sought to maintain the Union amidst growing sectional divides.

In the immediate aftermath of Taylor's death, the nation was in a state of uncertainty. Fillmore, who had spent nearly 20 years in public service and had previously served in the House of Representatives, was relatively unknown outside of his home state of New York. His moderate approach to issues like slavery positioned him as a potential unifier among warring factions within the government, although his political beliefs would face significant tests.

Fillmore's presidency would ultimately be defined by his support of the Compromise of 1850, a series of legislative measures intended to address the balance of free and slave states as the nation expanded westward. His decisions, influenced heavily by the political landscape of the time and by advisors seeking to preserve national unity, would leave a lasting impact on the trajectory of the United States, although they could not stave off the inevitable civil conflict that lay ahead.