In this May 22, 1992 file photo, Ed McMahon, left, and host Johnny Carson are shown on "The Tonight Show" for their final broadcast in Burbank, Calif. With his debut as host of NBC's "The Tonight Show" 50 years ago this October, until he retired from the show on May 22, 1992, he was seen by more people on more occasions than anyone else in American history. "Johnny Carson: King of Late Night," a two-hour "American Masters" portrait premiers Monday at 9 p.m. EDT on PBS. (AP Photo/Douglas Pizac, file)