In 1965, when President Lyndon B. Johnson underwent surgery, his Vice President served as acting President of the United States for exactly three hours. Who was this v.p., and what kind of surgery ?

On October 8, 1965, President Lyndon B. Johnson was admitted to Bethesda Naval Hospital for a common but necessary operation to remove his gallbladder and a kidney stone. While he was under anesthesia for the three-hour procedure, his presidential powers were temporarily transferred to his second-in-command, Vice President Hubert H. Humphrey. This made Humphrey the acting president, responsible for the command of the nation and its military until Johnson was awake and able to resume his duties.

This transfer of power was a significant, though informal, moment in U.S. history. At the time, the 25th Amendment, which formally codifies the process for presidential disability and succession, had not yet been ratified. Johnson instead created a voluntary precedent by sending letters to congressional leaders outlining the temporary arrangement. The event is also famously remembered for Johnson's characteristically brash behavior afterward; eager to prove his vitality, he lifted his shirt for photographers to proudly display his large surgical scar. While Humphrey's time at the helm was brief, the situation highlighted the need for a clear constitutional procedure, helping to spur the ratification of the 25th Amendment just two years later.