At the end of 1988, Dunham was told by James McCawley, a talent booker for "The Tonight Show with Johnny Carson", that Dunham would be given a spot on the program. Though the 26-year-old Dunham was elated that his 10-year goal was arriving two years early, McCawley later cancelled Dunham's appearance after attending, with Roseanne Barr, a public performance of Dunham's the day before Dunham's scheduled "Tonight Show" taping. McCawley informed Dunham on the day of the scheduled taping that he had been wrong in his initial assessment of Dunham, whom he now said was not ready for "The Tonight Show". His dreams dashed, the humiliated Dunham continued to tighten his act in Los Angeles clubs, performing same six minute segment with Peanut a total of nine times for McCawley over the next few months. Finally at the Ice-House in Pasadena in April 1990, after Dunham did the same segment, McCawley informed Dunham that he would finally get his "Tonight Show" appearance. Dunham and Peanut appeared on "The Tonight Show with Johnny Carson" on April 6, 1990, alongside guests Bob Hope and B.B. King. Following his bit, he was invited to sit on Johnny Carson’s couch, a mark of approval that only three comedians had ever garnered during their first Carson appearance. Upon sitting down next to Carson's desk, Dunham pulled out Walter, who told Carson sidekick Ed McMahon, "Stop sending me all your damn mail." At the time, Dunham saw his "Tonight Show" appearance as his big break, but was frustrated at his parents' initial disapproval over Walter's use of the words "hell" and "damn", and he would toil in obscurity for another twelve years, continuing his stand up at venues such as The Improv chain, and appearing in small roles on TV. One of these was such as a 1996 episode of "Ellen", in which he appeared with Walter. Dunham also appeared with Walter in a TV commercial for Hertz. Dunham would appear on "The Tonight Show" a total of four times, as well as similar TV venues such as "Hot Country Nights", appearing in one segment on that show with singer Reba McEntire. This exposure helped make Dunham a large theater headliner, a rare accomplishment for a ventriloquist, but by the mid 1990s, his television appearances had dwindled, and with them, so did his stage audiences.