"Suddenly"

 

The American Theatre in Newhall appears in the opening credits of Lewis Allen's film "Suddenly" (United Artists, 1954). Frank Sinatra stars as the leader of a group of mobsters planning to assassinate the President when he visits the small town of Suddenly, California. Also featured are Sterling Hayden, Kim Charney, James Gleason and Nancy Gates. The cinematography was by Charles G. Clarke. 

Robby Cress comments in "Suddenly (1954) Film Locations," a 2010 post on the Dear Old Hollywood blog:

"The film opens with a montage of the town. One of the buildings that we see is the old American Theatre located at 24527 Spruce Street. The theatre, which was built by the western film star William S. Hart, opened in 1941 and operated as a theatre until 1965. Today the building still stands and is currently the local American Legion Hall."

 

Thanks to Jonathan Raines for spotting the Dear Old Hollywood post. James Gleason, who appears in this film, had earlier appeared in "Earl of Puddlestone," one of the films that opened the American Theatre in 1941. 

 

Kim Charney checking out a poster for "Beachhead," a February 1954 release (also from United Artists) with Tony Curtis, Frank Lovejoy and Mary Murphy. His mother, who lost her husband in the war, tries to shield him from violence. She doesn't want him to see war movies. Or even own a cap pistol. 

 

Sterling Hayden as the sheriff comes along asking about the kid's mother. He's been trying to talk her into a romance. They head to the store to buy a cap pistol.

See the page about the American Theatre on the Los Angeles Theatres site for more about the building. It's a design by S. Charles Lee. 

On IMDb: "Suddenly"