The presidency of Richard Nixon began at noon EST on January 20, 1969, when Richard Nixon was inaugurated as 37th President of the United States, and ended on August 9, 1974, when he resigned in the face of almost certain impeachment and removal from office, the only U.S. president ever to do so. He was succeeded by Gerald Ford, whom he had appointed Vice President after Spiro Agnew was forced to resign. Nixon took office after the 1968 presidential election, in which he defeated incumbent Vice President Hubert Humphrey. To great public approval, he began phased troop withdrawals by the end of 1969, sapping the strength of the domestic anti-war movement. Despite the failure of Operation Lam Son 719, which was designed to be the first major test of the South Vietnamese Army since the implementation of Vietnamization, the drawdown of American soldiers in Vietnam continued throughout Nixon's tenure.