Robert Francis "Bobby" Kennedy (November 20, 1925 – June 6, 1968), also called RFK, was the United States Attorney General from 1961 to 1964 and a US Senator from New York from 1965 until his assassination in 1968. He was one of US President John F. Kennedy's younger brothers, and also one of his most trusted advisors and worked closely with the president during the Cuban Missile Crisis. He also made a significant contribution to the African-American Civil Rights Movement. After his brother's assassination in late 1963, Kennedy continued as Attorney General under President Johnson for nine months. He resigned in September 1964 and was elected to the United States Senate from New York that November. He broke with Johnson over the Vietnam War, among other issues. After Eugene McCarthy nearly defeated Johnson in the New Hampshire Primary in early 1968, Kennedy announced his own campaign for president, seeking the nomination of the Democratic Party. Kennedy defeated McCarthy in the critical California primary but was shot shortly after midnight of June 5, 1968, dying on June 6. On June 9, President Johnson declared an official day of national mourning in response to the public grief following Kennedy's death.