List of vice presidents of the United States
There have been 49 vice presidents of the United States since the office came into existence in 1789. Originally, the vice president was the person who received the second most votes for president in the Electoral College. However, in the election of 1800 a tie in the electoral college between Thomas Jefferson and Aaron Burr led to the selection of the president by the House of Representatives. To prevent such an event from happening again, the Twelfth Amendment was added to the Constitution, creating the current system where electors cast a separate  ballot for the vice presidency. The vice president is the first person in the presidential line of succession and assumes the presidency if the president dies, resigns, or is impeached and removed from office. Nine vice presidents have ascended to the presidency in this way – eight (John Tyler, Millard Fillmore, Andrew Johnson, Chester A. Arthur, Theodore Roosevelt, Calvin Coolidge, Harry S. Truman, and Lyndon B. Johnson) through the president's death and one (Gerald Ford) through the president's resignation. In addition, the vice president serves as the president of the Senate and may choose to cast a tie-breaking  vote on decisions made by the Senate. Vice presidents have exercised this latter power to varying extents over the years. Prior to adoption of the Twenty-fifth Amendment in 1967, an intra-term vacancy in the office of the vice president could not be filled until the next post-election inauguration. Several such vacancies occurred—seven vice presidents died, one resigned and eight succeeded to the presidency. This amendment allowed for a vacancy to be filled through appointment by the president and confirmation by both chambers of the Congress. Since its ratification, the vice presidency has been vacant twice (both  in the context of scandals surrounding the Nixon administration) and was filled both times through this process, namely in 1973 following Spiro Agnew's resignation, and again in 1974 after Gerald Ford succeeded to the presidency. The amendment also established a procedure whereby a vice president may, if the president is unable to discharge the powers and duties of the office, temporarily assume the powers and duties of the office as acting president. Three vice presidents have briefly acted as president under the 25th Amendment: George H. W. Bush on July 13, 1985; Dick Cheney on June 29, 2002 and  on July 21, 2007; and Kamala Harris on November 19, 2021. The persons who have served as vice president were born in or primarily affiliated with 27 states plus the District of Columbia. New York has produced the most of any state as eight have been born there and three others considered it their home state. Most vice presidents have been in their 50s or 60s and had political experience prior to assuming the office. The youngest person to become vice president was John C. Breckinridge at 36 years of age while the oldest was Alben W. Barkley at 71  years of age. Two vice presidents—George Clinton and John C. Calhoun—served under more than one president. There are currently five living former vice presidents. The most recent former vice president to die was Walter Mondale on April 19, 2021. Subsequent public office. Twenty-six vice presidents held other high state or federal government positions after leaving the vice presidency. Fifteen went on to become president: John Adams, Thomas Jefferson, Martin Van Buren, John Tyler, Millard Fillmore, Andrew Johnson, Chester A. Arthur, Theodore Roosevelt, Calvin Coolidge, Harry S. Truman, Richard Nixon, Lyndon B. Johnson, Gerald Ford, George H. W.  Bush and Joe Biden (nine of them did so following their predecessor's death or resignation); and six served in the Senate: John C. Calhoun, John C. Breckinridge, Hannibal Hamlin, Andrew Johnson, Alben W. Barkley and Hubert Humphrey. Several served as a member of the U.S. Cabinet or as an ambassador in later administrations, or in state government.