Vice President of the United States the Twenty-fifth Amendment established a procedure for filling such a vacancy: This procedure has been implemented twice since the amendment came into force. The first instance occurred in 1973 following the October 10 resignation of Spiro Agnew, when Gerald Ford was nominated by President Richard Nixon and confirmed by Congress. The second occurred 10 months later following Ford's August 9, 1974 accession to the presidency upon Nixon's resignation, when Nelson Rockefeller was nominated by President Ford and confirmed by Congress. Had it not been for this new constitutional mechanism, the vice presidency would have remained vacant after Agnew's resignation and
Vice President of the United States but not actually become President of the United States in their own right. This understanding was first tested in 1841, following the death of President William Henry Harrison, only days into his term. Harrison's vice president, John Tyler, asserted that he had succeeded to the office of President, not just to its powers and duties. He took the presidential oath of office, and declined to acknowledge documents referring to him as "Acting President." Although some in Congress denounced Tyler's claim as a violation of the Constitution, he adhered to his position. Tyler's view ultimately prevailed when the Senate and House