Presidency of John F. Kennedy killed Oswald due to his own grief over Kennedy's death, but the assassination of Kennedy and the death of Oswald gave rise to enormous speculation that Kennedy had been the victim of a conspiracy. Kennedy was succeeded as president by Lyndon Johnson, who stated on November 27 that "no memorial or oration or eulogy could more eloquently honor President Kennedy's memory than the earliest possible passage of a civil rights bill for which he fought so long." President Johnson created the Warren Commission—chaired by Chief Justice Earl Warren—to investigate the assassination. The Warren Commission concluded that Oswald acted alone in
John F. Kennedy assassination conspiracy theories no evidence that the Soviet Union was involved in the assassination of President Kennedy. The House Select Committee on Assassinations also wrote: "The committee believes, on the basis of the evidence available to it, that the Soviet Government was not involved in the assassination of President Kennedy". According to some conspiracy theorists, the Soviet Union, with Nikita Khrushchev motivated by having to back down during the Cuban Missile Crisis, was responsible for the assassination. According to a 1966 FBI document, Colonel Boris Ivanov—chief of the KGB Residency in New York City at the time of the assassination—stated that it was