Of the 47 men who have served as vice president of the United States, 14 went on to serve as president as well. This includes such notable figures as John Adams, Thomas Jefferson, Theodore Roosevelt and Harry Truman.
A number of vice presidents also ran for president unsuccessfully, including Hubert Humphrey, Walter Mondale and Al Gore. The only vice president to never be elected to the office was Gerald Ford, who was chosen to replace Spiro Agnew after his resignation. While the vice presidency was a relatively powerless position through much of the 19th century, the powers of the office expanded greatly after World War II.