Acting President of the United States On April 4, 1841, only one month after his inauguration, President William Henry Harrison died. He was the first U.S. president to die in office. Afterward, a constitutional crisis ensued over the Constitution's ambiguous presidential succession provision (). Shortly after Harrison's death, his Cabinet met and decided that Vice President John Tyler would assume the responsibilities of presidency under the title "Vice-President acting President". Instead of accepting the Cabinet's proposed title, however, Tyler asserted that the Constitution gave him full and unqualified powers of the office and had himself sworn in immediately as President, setting a critical precedent for an
Oath of office of the Vice President of the United States office of President of the Senate. Up until the middle of the 20th Century, the Vice President-Elect nearly always would be sworn in by the highest-ranking officer of the US Senate which was the outgoing vice president or the President Pro Tempore of the United States Senate. Sometimes, although not always, a short address would be given by the new vice president to the Senate. The oath of office has been administered most by the President Pro Tempore of the United States Senate (last in 1925) for a total of 20 times. Others to give the oath of office include