PIONEERS OF TELEVISION: Sitcoms

They were the stars of the small screen in the early years of television, and much of the nation came to a halt whenever their shows aired. They strolled, sprinted, fought, laughed, cried and loved through worlds that took viewers to places past, present and future. As the originators of these innovative television formats, they provided an essential escape for millions of viewers who eagerly waited to watch them each week.

This episode focuses on five key sitcoms: "I Love Lucy," "The Honeymooners," "Make Room for Daddy," "The Andy Griffith Show" and "The Dick Van Dyke Show."

The last remaining Honeymooner, Joyce Randolph, offers surprising insights into the mind of Jackie Gleason. Similarly, Marlo Thomas speaks candidly about her father, Danny. Andy Griffith offers forceful opinions about the people and techniques that made his show work.

In a rare occurrence, both Mary Tyler Moore and Dick Van Dyke recount their years on "The Dick Van Dyke Show." Hundreds of episodes were culled for the most entertaining clips - including one particularly side-splitting bit by Don Knotts.