Saturday Night Live went on the air for the first time on October 11, 1975, from Studio 8H at NBC in New York, with the comedian George Carlin as host and a cast that included John Belushi, Chevy Chase, Dan Aykroyd, Gilda Radner and Jane Curtin. It was called NBC's Saturday Night at first, because a rival variety show had already taken the name Saturday Night Live, and it got its title a few years later when that rival folded. It is still running, which makes it one of the longest-lived entertainment programmes on American television.
It was a slot NBC had given up on. The network ran reruns of The Tonight Show on Saturday nights, and it handed the time to a producer, Lorne Michaels, who was told to fill ninety minutes for a young audience that network television had mostly stopped trying to reach. The format was borrowed from nowhere in particular: a live show, a guest host, a musical act, a resident repertory company, and a cold open, with the cast and crew in a building built for radio, not television.
The first show is remembered for a language-class sketch and for Carlin's monologue. Nobody at the network expected it to matter. It did matter. What made it matter was the next year, the presidential campaign of 1976, when Chevy Chase's fall as Gerald Ford and Dan Aykroyd's Carter were watched as closely as the campaign itself, and the show became part of how the country talked about its politics. That connection held.
It has been uneven. Its alumni ruled American comedy for two generations: John Belushi and Gilda Radner first, then Eddie Murphy, then the casts of the 1990s, and so on through the present. Michaels left for five years in the 1980s and returned. The show is still broadcast live, still from the same studio, and the guest host still stands in front of the same band, and the audience still does not know what will happen, which is the point of doing it live.