A celebration of the show's 50th season relives the big moments, the famous people and the faraway places from the news program's five decades on air. Segments include: John McCain; Mick Jagger; Bill and Hillary Clinton; Ayatollah Khomeini; Barack Obama; Johnny Carson; Muhammad Ali; Jackie Gleason; Beyoncé; George W. Bush; Bashar al-Assad; guilt-ridden Kennedy Secret Service agent Clint Hill.