Lyndon B. Johnson (August 27, 1908 – January 22, 1973) was the 36th President of the USA, he died two days after the beginning of his second term, the Vice President was immediately sworn in that evening.
LBJ died in office on January 22, 1973. Vice President Hubert Humphrey was sworn in later that evening. Humphrey did not seek re-election in 1976. Instead, Rev. Martin Luther King Jr. ran for president on the Democratic side in 1976 and won in one of the largest landslides ever.