

During its run, 635 episodes were broadcast, of which 233 were 30 minutes and 402 were 60 minutes in length. The series expanded to an hour in length with season seven and began filming in color in season 12. Gunsmoke was originally a half-hour program filmed in black-and-white. In the United Kingdom, Gunsmoke was originally broadcast under the title Gun Law. The first episode aired in the United States on September 10, 1955, and the final episode aired on March 31, 1975. The series ran for 20 seasons, making it the longest-running Western in television history.

Gunsmoke is an American Western television series developed by Charles Marquis Warren and based on the radio program of the same name. Clockwise from top: Ken Curtis (Festus), Arness (Matt), Amanda Blake (Kitty) and Milburn Stone (Doc) in 1968
