James Cagney's character of Robert Emmett 'Bob' Sharkey was originally based on the World War II director of the Office of Strategic Services (OSS), William Donovan (i.e. Major General William Joseph Donovan, USA, GCSS, KBE) as well as the spy agency being based on the O.S.S. Donovan objected to this, particularly the story element that the OSS had been infiltrated by an enemy German Nazi agent spy. Alas, the spy agency became the "077" and any of Cagney's character similarities with Donovan were removed.
Due to military intelligence and secrecy reasons, American Hollywood Studios were prevented by the US Government from mentioning the OSS (the Office of Strategic Services) in movies during World War II. Alas, the OSS is not mentioned in this movie.
Story is based on Peter Ortiz who was an OSS agent in world war two in France.
The film's director, producer, and one of the writers had worked previously on another spy film for the same movie studio (20th Century Fox) called The House on 92nd Street (aka Now It Can Be Told (USA)). Interestingly, both films utilized street addresses as their film titles.
The relevance of an address as this film's title is that '13 Rue Madeleine' is the address of German Nazi Gestapo headquarters in Le Havre, France during the Nazi German occupation of France in World War II and this is where the spy mission takes this film's heroes.
This film's director, Henry Hathaway, once said of this movie: "I stole the plot of 'The Virginian' and used it. I'd always wanted to make that story anyway."
This movie's opening prologue states: "No single story could ever pay full tribute to the accomplishments of the U.S. Army Intelligence in World War II. Working secretly behind enemy lines, in close cooperation with our Allies, its brilliant work was an acknowledged factor in the final victory. In order to obtain the maximum of realism and authenticity, all the exterior and interior settings in this Motion Picture were photographed in the field - - and, whenever possible, at the actual locations."