The film was originally intended by Columbia Pictures' production chief Harry Cohn as a vehicle for Rita Hayworth, a follow-up to the extremely popular Gilda (1946). Cohn thought that the pairing of Hayworth and Humphrey Bogart would be a guaranteed money maker. However, Hayworth was in the middle of a contract dispute with Columbia, and refused to make the film, so she was replaced by Lizabeth Scott, who was borrowed from Paramount Pictures' producer Hal B. Wallis.
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.
At the bar, Coral orders a Ramos Gin Fizz. Invented in 1888 by Henry C. Ramos, owner of the Imperial Cabinet Saloon in New Orleans, it is a modified gin fizz that includes egg white and heavy cream, and the original recipe called for a 12-minute shake time.
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.