Theodore Roosevelt, cultivated a new respect among Americans for the vice presidency.

Topical Press Agency/­Getty Images

The Evolution of the U.S. Vice Presidency

Right out of the gate, it appeared that the person serving as vice president had a clear shot at winning the presidency after the incumbent leader finished serving. John Adams, vice president to the first president, George Washington, won the election after Washington's tenure. President Adams' second in command, Thomas Jefferson, was elected president right after serving his term as vice president. Jefferson's transition to power marked the beginning of a long dry spell for incumbent vice presidents, however. After his tenure, only two more vice presidents were elected president directly in the next election, Martin Van Buren in 1836 and George H.W. Bush in 1988 [source: Encarta]. What happened?

Gifted with hindsight, historians generally point to the passage of the 12th Amendment as a major turning point in the importance of the position of vice president. No longer was the vice president a viable (although defeated) contender for the position of president; instead, it was left to the political parties to nominate presidential and vice presidential candidates for national elections. This nomination inadvertently created the party ticket, and the custom of choosing vice presidential candidates based on their appeal to a constituency rather than their ability to lead was born. Even in modern times, vice presidents are generally chosen to offset a presidential candidate so that combined, a ticket will appeal to as many voters as possible.

­Throughout the 19th century, the vice president had no real role in government outside of his duty as Senate president. This changed with Theodore Roosevelt. Following the assassination of the president, William McKinley, in 1901, Roosevelt ascended to the presidency and became one of the most active and popular presidents in American history. President Woodrow Wilson's vice president, Thomas Marshall, became the first in 116 years to attend Cabinet meetings (the last Vice President to do so being John Adams).

The early 20th century saw a revving of the vice presidential engine, with the office going at full throttle under President Franklin Roosevelt. President Roosevelt had three vice presidents serve under him during his 12 years in office, and he afforded them more power than any others before. Roosevelt included his vice presidents at Cabinet meetings (although President Warren Harding was the first president to attempt including his vice president, Calvin Coolidge, at the meetings). President Roosevelt also made it customary for the vice president to be involved in negotiations with Congressional leaders over legislation.

Roosevelt also had a major indirect influence on the vice presidency; he kept his last vice president, Harry Truman, out of the loop on secret projects, such as the Manhattan Project to create a nuclear bomb. When Roosevelt died in office, Truman took over in 1945 as a wartime president without any sure knowledge of the bomb. Four years later, Congress passed a law that requires the vice president have a permanent seat on the National Security Council, which briefs and advises the executive branch on military and intelligence.

In the modern era, presidents have given more responsibilities to the vice president. President John Kennedy put Vice President Lyndon Johnson in charge of the space program and the development of NASA. Under President Gerald Ford, Vice President Nelson Rockefeller headed a committee that investigated abuses by the CIA, including the testing of LSD on unsuspecting Americans.

Vice President Richard Nixon further expanded the office both figuratively and literally. While Nixon was in the Vice President office, the vice presidential offices opened in the Executive Office Building (in addition to the traditional office space in the Senate Building), and the vice presidential staff was expanded as well.

Take a closer look at the roles and responsibilities of the U.S. vice president on the next page.