Jerry Adler, younger brother of Larry Adler, taught James Stewart how to hold the harmonica and mime the playing for the movie, and was the person who did the actual playing of the harmonica music supposedly done by Stewart, who continued playing the instrument after the movie.
At Ma McCorkle's (Mary Gordon's) house, Police Lieutenant Grady (James Burke) is told about the tomato-throwing incident that had taken place earlier that day. When he says, "It must've been good", someone responds, "Good? It was perfect!", to everyone's amusement. This is in reference to a running joke in Paulette Goddard's earlier film, Second Chorus (1940), where the gag "Vas good?" "Vas per-fect" (in a Russian accent) is exchanged in a couple of scenes.
Re-titled "Jimmy Steps Out", this film's earliest documented television broadcast occurred Sunday, May 23, 1948, in Los Angeles, California on KTLA (Channel 5). On Sunday, June 20, 1948, it was the first feature film shown on New York City's newly launched television station, WPIX (Channel 11), which began broadcasting on June 15, 1948. It was followed on succeeding Sundays by the Hal Roach package of three dozen feature films, produced between 1931 and 1943 and newly acquired for television broadcast by Regal Television Pictures. In Baltimore, it first aired Saturday, July 3, 1948 on WMAR (Channel 2), in Detroit, Sunday, July 1, 1949 on WXYZ (Channel 7), in Boston Thursday 19 August 1948 on WBZ (Channel 4), in Cincinnati Wednesday 28 September 1949 on WKRC (Channel 11), and in Philadelphia, Saturday, November 5, 1949 on WCAU (Channel 10).
The failure of the original copyright holder to renew the film's copyright resulted in it falling into public domain, meaning that virtually anyone could duplicate and sell a VHS or DVD copy of the movie. Therefore, many of the versions of this film available on the market are either severely (and usually badly) edited and/or of extremely poor quality, having been duped from second- or third-generation (or more) copies of the film.
"Pot O' Gold" was a radio program that featured musical routines; this film is a movie version of that radio program.
James Stewart shot this film simultaneously with Ziegfeld Girl (1941) at MGM, and shuttled between studios as required. He said that he caught the movie by accident on television and watched the scene where he is squirted with a seltzer bottle. Initially he thought he had tuned-in to a sitcom, until he realised it was one of his own movies.
The only full-length feature produced by James Roosevelt, eldest son of FDR, although he was Executive Producer on seven shorts the same year. His short career in Hollywood was in part to protect his father from accusations of nepotism following James's previous Hollywood appointments.