Twenty-second Amendment to the United States Constitution
The Twenty-second Amendment (Amendment XXII) to the United States Constitution sets a limit on the number of times an individual is eligible for election to the office of President of the United States, and also sets additional eligibility conditions for presidents who succeed to the unexpired terms of their predecessors.
William Henry Harrison
Harrison's cabinet insisted that Tyler was "Vice President acting as President". After the cabinet consulted with the Chief Justice Roger Taney, they decided that if Tyler took the presidential Oath of Office, he would assume the office of president. Tyler obliged and was sworn into office on April 6, 1841. Congress convened in May, and after a short period of debate in both houses, it passed a resolution that confirmed Tyler as president for the remainder of Harrison's term. Once established, this precedent of presidential succession remained in effect until the Twenty-fifth Amendment was ratified in 1967, following the assassination of John F. Kennedy and the succession of Lyndon B. Johnson to the presidency in 1963. The Twenty-fifth Amendment dealt with the finer points of succession, defining the situations in which the vice president would serve as acting president, and in which situations the vice president could become president.