David Letterman has cultivated a national following of ardent fans with his offbeat humor and sophisticated smart-aleck comic style. That style was honed on his nighttime talk show on NBC, Late Night with David Letterman, which debuted in 1982 in the hour following The Tonight Show Starring Johnny Carson. Roughly a decade later, in 1993, Letterman changed time periods and networks, as The Late Show with David Letterman began broadcasting on CBS at 11:30 P.M., a more accessible and lucrative time slot.

     Letterman rose to fame as talk show host and celebrity during a period in television history when late-night talk, a unique TV genre, began to stretch beyond the confines of the solid, long-standing appeal of NBC's Tonight Show. His influence and appeal increased steadily until, by 1995, he was the most­ watched and highest-paid late-night television talk show host in the United States. In 1996, however, NBC's The Tonight Show with Jay Leno began occasionally overtaking Letterman's programs in the ratings, and by the early 21st century, Leno's show was regularly attracting a larger audience than Letterman's. Although he has slipped a bit in the ratings, Letter­ man's audience remains considerable (and represents a demographic that advertisers greatly desire), and he remains a favorite of critics, many of whom prefer his more pointed and acerbic style of comedy to the milder, "nice guy" humor of his Tonight Show rival.

     Letterman began his career in broadcasting in his native Indianapolis, Indiana, where he worked in both television (as an announcer and weekend weatherman) and radio (as a talk show host). In 1975 he moved to Los Angeles, where he wrote comedy, submitted scripts for television sitcoms, and even appeared on various sitcoms and game shows. He performed stand­ up routines at the Comedy Store, where he met Leno, by then a seasoned comedian, and Merrill Markoe, with whom he would later have a long-time professional and personal relationship. In 1978 Letterman made his first appearance as a stand-up comic on The Tonight Show Starring Johnny Carson. Shortly thereafter he was hired by NBC to host a morning television talk show, which was broadcast from New York. Although the program lasted only a short time, it was the comic forerunner to his late-night NBC hit.

     Late Night with David Letterman, programmed to follow the familiar Carson formula, was a different kind of talk show, a format in which the comedy usually outshone the interviews. Letterman's fascination with humor of the mundane, his quirky antics (Stupid Pet Tricks, Elevator Races, the Top Ten List), and his overall irreverence came on the heels of a new, hip style of comedy exemplified by NBC's late-night comedy sketch program, Saturday Night Live (SNL). His style was attractive to a younger television audience that had been loyal supporters of SNL since the mid-1970s. However, Letterman retained The Tonight Show comedy/interview format. Letterman was neither as emotionally nor as politically involved in his interviews as Paar had been. More like Carson, he exhibited a cool detachment from, and more middle-American stance toward, the political and social events of the day.

     During his tenure at NBC, Letterman occasionally served as guest host on The Tonight Show in Carson's absence. He shared that job with several others, most notably Joan Rivers and Leno. Letterman's interview style on both The Tonight Show and Late Night was sometimes easygoing, sometimes mocking. Indeed, a number of guests found him to be a mean-spirited interviewer, and some celebrities claimed he was adolescent at best, highly offensive at worst. Nevertheless, he had a loyal following of late-night watchers, and he inspired a large number of discussions, references, and imitations among fans, in the media, and throughout popular culture.

     By the early 1990s, speculation centered on which of the two most successful young comedians, Leno or Letterman, would be Carson's successor upon his retirement. After intense network negotiations with both potential Tonight Show hosts-and considerable public attention-Leno succeeded Carson. At that point, Letterman accepted a generous offer from CBS to host his own show, and the two men became direct competitors at 11:30 P.M. on weeknights. On CBS, Letterman's popularity grew. He maintained much the same approach to comedy he had at NBC, but he softened some of his angry edge and irreverence. Some commentators attributed the changes to a desire, on both his part and the network's, to broaden his audience in the earlier time slot.

     In the late 1990s and early 2000s, The Late Show was regularly visited by political figures eager to reach Letterman's large and diverse audience, including viewers who might not watch more traditional news programming. During his tenure as New York City mayor, Rudolph Giuliani made a number of appearances, not just for interviews but also as a reader of Top Ten lists and participant in comedy sketches. Other notable politicians to appear with Letterman have included President Bill Clinton, presidential candidates Al Gore and George W. Bush, Hillary Clinton (when she was running to become senator for New York), and U.S Attorney General John Ashcroft (who played piano with The Late Show band). The ability of such political leaders to stand up to the jibes of Letter­ man and to make the audiences laugh has increasingly been seen as a kind of test of their suitability for office. Similarly, news anchors such as Tom Brokaw, Dan Rather, and even Ted Koppel (whose Nightline program directly competed with The Late Show) have frequently sat for interviews with Letterman, who gives them exposure to viewers outside of the aging demographic group most likely to watch network news.

     In 2000 Letterman underwent heart bypass surgery after doctors discovered he had potentially life­ threatening arterial blockages. When he returned to his program several weeks after his surgery, the Late Show host allowed himself a rare display of emotion, bringing his doctors and nurses onstage to thank them publicly for their care. More generally, this health scare helped focus popular and critical attention on Letter­ man's maturation and his evolving status as a late­ night fixture of considerable influence.

     Over the next couple of years, two other notable events would throw even more light on the power wielded by The Late Show and its host in the television medium and American popular culture more broadly construed. On September 17, 2001, Letterman was the first comedic talk show host to return to the airwaves after the terrorist attacks on the United States of September 11. When the show opened, he appeared at his desk (foregoing the usual fanfare, music, and introductory humorous monologue) and spoke without a script for several minutes about his own sorrow, anger, and horror at the losses that had occurred. Admitting to the audience that he was unsure if he should be on the air, he told them, "We're going to try and feel our way through this, and we'll just see how it goes." Letter­man then followed his commentary with two inter­views: a serious discussion with CBS anchorman Dan Rather about the event that had occurred and a conver­sation with favorite Late Show guest Regis Philbin (who had also been on the last program before Letterman had surgery and the first after he returned to health). The approach taken by Letterman that night (including his tentative return to humor in a moment or two of gently mocking Philbin) was widely praised in the press, and other late-night comedians clearly took their cue from him as they too opened their first post­ attack shows with personal, joke-free reflections on the event.

     In April 2002, several months after The Late Show had settled back into its familiar comedy-talk format, Letterman again grabbed headlines, this time when it was revealed that ABC was making a bid to lure him away from CBS. If Letterman were to sign with ABC, it was announced, his show would replace Nightline, the venerable late-night news program that aired opposite The Late Show and The Tonight Show. To many observers, ABC's willingness to sacrifice news analysis for Letterman's more advertiser-friendly-and therefore potentially more lucrative comedic fare signaled the degree to which U.S. networks had come to privilege profits over the public interest. Ultimately, Letterman decided to re-sign with CBS for several more years.

     Prior to weekday taping sessions, sidewalks outside the Ed Sullivan Theater in New York City, venue for The Late Show, are typically the site of long stand-by lines of those hoping for seats inside the already packed house. Letterman clearly remains a celebrity whose voice resonates in contemporary American culture.