The first U.S. President, George Washington, only ran for President twice. Washington felt that one person should not serve as President for a very long time. Following this tradition, no future President served for more than two terms until Franklin Roosevelt was elected to four terms. Not long after he died, the Constitution was amended by the 22nd amendment so that a President could only serve two terms.

The 22nd Amendment, proposed and ratified following the Roosevelt presidency, provides that "No person shall be elected to the office of the President more than twice ..." Further, Vice Presidents who succeed to the presidency may be elected to two full terms as President if they have served less than two years of  their predecessor's term (up to 10 years of service). If they have served more than two years of a predecessor's term, they can be elected to only one additional term (between four and eight years of service, depending on when the Vice President succeeded to the presidency). It is unclear whether a two-term President could succeed to the presidency from the vice presidency or some other office in line of succession; experts disagree on whether this would be constitutional.