At the dawn of the TV era in the 1950s, Steve Allen's zany spontaneity turns Tonight into a hilarious and unexpected hit. But in the early 1960s, it's Jack Paar's captivating, quirky personality and Johnny Carson's impeccably hip humor that transform late night into an enduring television staple.

Johnny Carson deftly navigates the turbulent 1960s to elevate The Tonight Show into a cultural touchstone, enshrining himself as the undisputed king of late night. His success begets competition with the emergence of Dick Cavett and Merv Griffin.

As the 1980s dawn, David Letterman reinvents late night comedy for a new generation, rescuing comedian Jay Leno's nearly flamed-out career in the process. But Johnny Carson's enduring comic appeal spawns endless speculation over his eventual successor.