A ceremony honoring President John F. Kennedy took place Friday in Dallas, Texas.  Dallas Mayor Mike Rawlings said the eras of hope and hatred collided on this day in Dallas 50 years ago.

Historian David McCullough was one of hundreds of people from across the globe who braved the cold to attend the ceremony at Dealey Plaza.  He pointed out how ambitious JFK was to make the world better and how things needed to be done.  Bells tolled after a moment of silence marking the exact moment the President was assassinated. 

Those who believe John F. Kennedy's assassination was part of a conspiracy haven't been silent on this 50th anniversary of his death. Several of them demonstrated during Friday's ceremony in Dallas. They wore t-shirts showing Kennedy's image on the half-dollar coin with a bullet hole, and they silently pointed to the ``grassy knoll'' from where some conspiracy theorists believe shots were fired.