In January 1965, Johnny Carson appeared at Lyndon Baines Johnson's presidential inauguration gala. Carson took the stage directly opposite the president and bragged "I've done more for birth control than Enovid." The claim is questionable, but it is vintage Johnny Carson. Like most Carson jokes, it looks neither particularly funny nor particularly racy on paper. In its delivery, however, Carson won much of the audience over, created a flurry of scandal, and effectively situated himself in American cultural history. Carson made one of television's greatest careers by playing his impish wit off his Midwestern charm, bringing the sexual revolution to middle America, middle America to the world, and establishing the form for television variety and humor that continues to dominate.

Carson was born on October 23, 1925 in Corning, Iowa, and spent the first eight years of his life moving throughout Iowa as his father established a...