The United States marks the 50th anniversary of the assassination of President John F. Kennedy on Friday with memorial ceremonies and moments of silence.
President Barack Obama has ordered flags across the United States to fly at half staff to honor the late president, who was gunned down late in the third year of his single term in office.
Church bells will ring in Dallas, Texas -- the southwestern city where President Kennedy was gunned down. There will also be moments of silence at locations important in the life of the slain president. Pulitzer Prize-winning historian David McCullough will read from some of Mr. Kennedy's speeches.
The CBS television network will live-stream its original news bulletins from the event.
Mr. Obama has called his revered predecessor an "extraordinary public servant" who had broad vision and sober idealism. Mr. Obama laid a wreath at President Kennedy's grave at Arlington National Cemetery on Wednesday.
A survey of Americans (by CNN and ORC International) shows that President Kennedy is the most popular president of the last half century, with 90 percent approving of his handling of the presidency. No other U.S. president comes close to that rating.
Mr. Kennedy's presidency was about 1,000 days old and he was just 46 when he was shot dead while riding in an open-top limousine. The fatal shot destroyed most of the president's brain, shocking witnesses by its brutality.
The crime stunned the world and left even the president's adversaries, such as Soviet leader Nikita Khrushchev, grieving and speechless.
Most Americans spent the weekend in tears, watching the president's young widow, Jacqueline, and their two small children mourn publicly.
The president's assassin, Lee Harvey Oswald, was shot dead in police custody on live television two days after the death of the president. His motive will likely never be known. Oswald was a former U.S. Marine who defected to the Soviet Union in 1959, then returned to the U.S. in 1962.