The 22nd Amendment to the U.S. Constitution, which was ratified in 1951, instructs that "No person shall be elected to the office of the President more than twice, and no person who has held the office of President, or acted as President, for more than two years of a term to which some other person was elected President shall be elected to the office of President more than once." Dwight D. Eisenhower was the first President who was limited to two terms by the 22nd Amendment.