In The Oath, we find ourselves in Buffalo, New York, in March 1849, where Millard Fillmore, portrayed by William Powell, is preparing for his new role as Vice President of the United States. The atmosphere is tense, as Fillmore is acutely aware of the political crisis brewing in Congress over the contentious issue of slavery. His wife, Abigail, played by June Dupree, provides a grounding presence as they reflect on their journey from humble beginnings to the heights of political power. The couple's deep connection is evident as they discuss their hopes and fears about moving to Washington and the responsibilities that await them.