In the first episode of the Dennis the Menace television show, Dennis embarks on one of his most devious schemes by trying to get Alice and Mitchell to take him to the see the new Glenn Ford picture instead of the two of them going out alone (see recap of Episode 1, Dennis Goes to the Movies for the full recap).
At this point in television show broadcasting, you didn’t really see footage of other current programs on the TV’s of your favorite television family. The program that was on was either alluded to or an obvious homage to a particular show was shown (think Car 54‘s “Crime Busters” program). I feel like this “must see” Glenn Ford movie was the 1956 release The Fastest Gun Alive.
Despite Alice having said that she wanted to see the “NEW Glenn Ford picture,” this seems the more likely choice keeping in mind that Dennis the Menace’s first season aired starting in fall of 1959. The pilot was filmed several months prior to the actual show airing, according to Gloria Henry in the program’s special features, and the actual script for the pilot could have been written some time before that. We will presume that the pilot was filmed six months prior to the show airing on October 4, 1959 which would put filming as late March or early April of that year. Given that Dennis is in a light jacket for the program (which he usually isn’t), cool weather for the exterior shots could explain this. This would put the script as being written in early 1959 or late 1958 at the latest.
The Fastest Gun Alive was released on July 12, 1956. It probably wouldn’t have trickled down to the local theaters for several months afterwards, and it still could have been a “new” Glenn Ford picture to Dennis’ hometown even a couple of years later. The only other Glenn Ford western released during this time starred Ford and Jack Lemmon and it was named Cowboy. I don’t remember having seen this film myself, but I know it must not have been a heavy film based on its description and Glenn’s co-star.
Dennis specifically mentions how fast Glenn Ford’s character was with a gun and the fact that a dumb ole girl is around to interfere with all of the “Ka-pow”ing gunshots. Jeanne Craine (I love her in State Fair!) co-starred in this film and would definitely have been a love interest.
No actual footage or dialogue from the film appears in Dennis, only generic action scene sounds such as gunfire and a movie score that could easily have been recreated or faked by show’s staff. Given all of this, I’m pretty sure my guess is right!