 Due to the postponement of the swearing-in ceremony until March 5, various friends and colleagues of Senator David Atchison asserted that on March 4–5, 1849 he was acting president of the United States.They argued that, since both President James K. Polk and Vice President George Dallas ceased to hold their offices at noon on March 4, and since neither Taylor nor Fillmore had yet sworn their prescribed oath of office, both offices were vacant.As a result, they claimed, in accordance with the Presidential Succession Act of 1792, Atchison, by virtue of being the President pro tempore of the United States Senate, was the nation's acting chief executive during the Interregnum.