Answer:
This is true. Because of his responsibility in the Watergate scandal, in order to avoid being impeached by the Senate, president Richard Nixon resigned on August 9, 1974. He was replaced by Gerald Ford. Spiro Agnew, who had been in the Republican presidential ticket in 1972, resigned in December 1973. Nixon nominated Ford as vicepresident based on the 25th Amendment. After Nixon´s resignation, Ford was sworn in as president and nominated Nelson Rockefeller as vicepresident in December 1974. So, this is correct, both Ford and Rockefeller held the highest office in the US without having been voted for by the American people.
Explanation: