The role of Coral Chandler was originally intended for Rita Hayworth, but she already had been cast by her estranged husband, Orson Welles for the role of Elsa in The Lady from Shanghai (1947). Also, according to Ben Mankiewicz's introduction to this movie on TCM, Ms. Hayworth was engaged in a contract dispute with the studio at the time, and refused the role.
In the train, after they discover that Drake is to receive the Medal of Honor, Murdock quips that maybe the president will let Drake "sit on top of his piano". This is a reference to a then-scandalous photo of Harry S. Truman playing piano with a leggy blonde on top that was taken at the National Press Club in 1945. The blonde was Lauren Bacall, later the wife of Humphrey Bogart.
Film debut of Lillian Wells, whose movie career consisted of uncredited roles in six films, all of which were released in 1947. Here, she was on screen for about five seconds as the pretty girl who wanted to use the pay phone Murdock was using for a long distance call.
Humphrey Bogart was borrowed from Warner Bros. for this film. This annoyed him because in addition to his regular contract fee, Columbia paid Warner Bros. extra for the loan-out of one of its biggest stars.