Arness joined the cast of "Gunsmoke" at the recommendation of his good friend, the Western legend John Wayne (via Outsider). Thanks to Wayne, Arness became the stuff of TV legend, appearing in all 635 episodes of the series' 20-season run. While his cast mates' episode counts were also impressive, none could touch Arness' record. Weaver's fan-favorite character exited in Season 9, and Miss Kitty left the series in 1974. The only cast member to come close was Stone, who portrayed Doc Adams for all 20 seasons. In addition to the 20 years "Gunsmoke" was on the air, Arness would reprise his role as Dillon in five made-for-TV "Gunsmoke" films in the '80s and '90s (via IMDb).
After playing Dillon for two decades, Arness set the record for longest portrayal of a single character, a feat only surpassed by Mariska Hargitay in "Law & Order: Special Victims Unit." If it were up to Arness, however, he would have played the character for a few more years. But in 1975, CBS abruptly canceled the series despite consistent ratings success through the 1970s (via Nielsen Ratings). "We didn't do a final [Gunsmoke] wrap-up show," Arness told the Amarillo Globe-News. "We finished the 20th year, we all expected to go on for another season, or two or three. The [network] never told anybody they were thinking of canceling" (via GunsmokeNet).
