Jackie Kennedy made private White House visit eight years after JFK's death

Letters on display at Nixon and Kennedy libraries show how former first lady requested to slip in unobtrusively' in 1971

Fifty years ago, Jacqueline Onassis entered the White House for her first visit since her husband, John F Kennedy, was assassinated.

By 1971, it had been almost eight years since Onassis had been in her former home, but she had written to the then first lady, Pat Nixon, to request a private visit ahead of the unveiling of Kennedy's official portrait.