Mary Astor's off-screen notoriety was instrumental in her casting. She was known for being adulterous, having had an affair with John Barrymore, widowed in a plane crash, a multiple bride, and an alcoholic. She also kept a diary of her various sexual exploits that was introduced as evidence in a custody hearing against her estranged husband over who should look after their daughter. The gossip rags thrived on this story.
Walter Huston did his uncredited cameo as a good luck gesture for his son. He had to promise to the notoriously tight head of studio, Jack L. Warner, that he wouldn't charge for his appearance.
Walter Huston: Capt. Jacobi.
A copy of John Huston's first draft script was accidentally sent to studio head Jack L. Warner as well as the film's designated producer, Henry Blanke. To his surprise, Warner loved the script and insisted that Huston started shooting it immediately.
According to Mary Astor in her autobiography 'A Life on Film', Sydney Greenstreet was very nervous before his first scene and remarked," Mary dear, hold my hand, tell me I won't make an ass of meself!"
After Geraldine Fitzgerald had made it clear that she wasn't interested in doing the film, the next port of call for the part of Brigid O'Shaughnessy was Mary Astor. John Huston and Humphrey Bogart visited her at her home to talk over the script and she was immediately smitten by their palpable excitement in the project. Already familiar with the novel, Astor was even more impressed with the screenplay which she thought was a "humdinger". She signed on straight away.
Although he story-boarded every scene, John Huston was open to abandoning his plans if his more-experienced cast came up with something better. He estimated that three-quarters of the time, he used his original set-ups, but for the remaining quarter, he adopted ideas that the cast had come up with during rehearsal.
Although this was the 62-year old Sydney Greenstreet's film debut, he had already worked as a prominent stage actor for forty years.
As a joke, Walter Huston kept fumbling his walk-on cameo so his son John had to do lots of different takes.
At 357 pounds, 60-year-old British newcomer Sydney Greenstreet was so large that the studio had to specially manufacture his entire wardrobe for the role of Kasper Gutman.
Contrary to popular opinion, "It's the stuff that dreams are made of", spoken by Humphrey Bogart, is not the last line in the picture. Immediately after Bogart says that, Ward Bond, playing a detective, says, "Huh?" making that the last line in the picture.
Filming was completed in two months at a cost of less than $300,000.
For decades, this film could not be legally shown on US TV because of its underlying sexual suggestion.
Frustrated at seeing his script for Juarez rewritten by Paul Muni, the film's star, John Huston vowed that from then on he would direct his own screenplays and therefore not have to see them get meddled with. He was fortunate in that he had a staunch ally in the form of producer Henry Blanke who was happy to fulfill Huston's wish.
Gutman and Wilmer are referred to as "Fat Man" and "Little Boy". These are the names used for the two atomic bombs dropped on Nagasaki and Hiroshima respectively.
Having seen how profligate novice writer-directors like Orson Welles and Preston Sturges had been, Warner Brothers were not keen on giving John Huston too much control. They acquiesced when Huston agreed to do an immediate polish on the script for Sergeant York.
In 2007, the American Film Institute ranked this as the #31 Greatest Movie of All Time.
In all the scenes involving Mary Astor, there's a suggestion of prison. In one scene, she wears striped pyjamas, the furniture in the room is striped and the slivers of light coming through the Venetian blinds suggest jailcell bars. When she steps into the elevator at the end of the film, the lighting also suggests bars.
In real life, Dashiell Hammett had been a one-time operative for Pinkerton's Detective Agency. Brigid O'Shaughnessy was partly based on his secretary, Peggy O'Toole, and partly on a woman who once employed him to fire her housekeeper. Joel Cairo was based on a man Hammett picked up on a forgery charge in 1920, while Wilmer, the gunman, was drawn from a petty criminal who went by the nickname of "The Midget Bandit".