The production had a fake working title, "Highway 66", so that the shoot of the controversial novel would not be affected by union problems. Much of the dire straits portrayed in the film continued during and after the release of the movie.
Prior to filming, producer Darryl F. Zanuck sent undercover investigators out to the migrant camps to see if John Steinbeck had been exaggerating about the squalor and unfair treatment meted out there. He was horrified to discover that, if anything, Steinbeck had actually downplayed what went on in the camps.
Henry Fonda kept the hat he wore in the movie for the rest of his life, until before he passed away in 1982 he gave it to his old friend Jane Withers. Apparently he and Withers, when she was an 8 year old girl and he a young man, did a play together before Fonda made movies. Fonda was so nervous to go onstage that little Jane took his hand, said a little prayer to ease his nerves, and the two of them became good friends for life.
Banks and the large farming corporations that controlled most California farms were not keen on the original novel (it was banned in some states and in several counties in California, and the book was not carried in the municipal library of author John Steinbeck's home town of Salinas, California, until the 1990s) and were even less thrilled that a film was being made of it. The Associated Farmers of California called for a boycott of all 20th Century-Fox films, and Steinbeck himself received death threats.
Henry Fonda, still struggling to became a big Hollywood star, tried to avoid being a contract player for 20th Century-Fox because he wanted the ability to independently choose his own projects (an increasing number of stars at the time were trying to gain such independence). But when the much-coveted part of Tom Joad was offered to him, Fonda hesitantly gave in and signed a contract to work with the studio for seven years because he knew it would be the role of a lifetime.
While filming the Joads' car traveling down the highway, John Ford wanted to add a shot showing the large number of caravans heading west, so the film's business manager stopped actual cars making the trek and paid the drivers five dollars to escort the Joads' jalopy for the cameras.
John Steinbeck was particularly enamored with the performance of Henry Fonda as Tom Joad, feeling that he perfectly encapsulated everything he wanted to convey with this character. The two became good friends. Indeed Fonda did a reading at Steinbeck's funeral.
Darryl F. Zanuck paid $100,000 for the rights to John Steinbeck's novel - a staggering amount of money at the time. Steinbeck only allowed the rights to be sold under the proviso that the filmmakers should show the material due reverence and treat the project responsibly.
Although the script conformed to the provisions of the Production Code, a number of potential "problems" had to be addressed. The list of suggested alterations or eliminations included a warning "not to characterize Muley as insane", the rewording of "certain of the lines which have reference to Rosasharn's pregnancy" (in the book, Tom teases Rosasharn and Connie with the line, "Well, I see you been busy"; in the film this is changed to, "Well, I see I'm gonna be an uncle soon"), the removal of a "toilet gag about Grandma" (early in the family's journey Rosasharn leads her out of a gas-station washroom, explaining, "She went to sleep in there"), the elimination of "specific mention of Tulare County [California]" and a request not to identify a town as "Pixley" (a town in Tulare County, CA, notorious for its ill treatment of migrant workers). It was also suggested that the film not show "Tom killing the deputy in self-defense".
Henry Fonda currently holds the record for the longest gap between acting Oscar nominations. His first nomination was for The Grapes of Wrath (1940) in 1940, his second was for On Golden Pond (1981) in 1981, 41 years later. He received one other Oscar nomination in the period between his two acting nominations, that was for producer of 12 Angry Men (1957) in 1957.
John Ford was considered an odd choice for director as he was a staunch conservative who would here be tackling a fairly political subject - the treatment of the Okies. Ford surprised his critics by delivering probably his most sensitive film.
Noah Joad simply vanishes after the scene of the family swimming in the Colorado River. In the book, Noah tells Tom he has decided to stay by the river. In the film, his disappearance is never explained.
Slightly more than halfway through the film, when the Joads pull over to fix a tire, Ma sits on the front fender while Tom crawls under the car. You can just barely hear him say, "Ma, get the hell off (the fender)," which would have been against language codes for films in the era.
Beulah Bondi was tested for the role of Ma Joad. Bondi, believing that she had the part, reportedly bought an old jalopy and moved to Bakersfield (CA) to live among the migrant workers in order to research the role. Bondi was reportedly extremely disappointed at losing the role.
In the book, John Steinbeck had the character of Casy parodying the song "Yes Sir, That's My Baby" by singing "Yes sir, that's my Savior/Jesus is my Savior/Jesus is my Savior now." The Motion Picture Production Code then in effect forbade use of the words "God" and "Jesus" except when used "reverently", so the script resorted to having him hum: "Mm-mmm, mmm, my Savior".
Producer Darryl F. Zanuck knew that Henry Fonda was desperate for the part of Tom Joad, so he let it be known that he was going to offer the part to Tyrone Power. Fonda pleaded with Zanuck for the part, and in order to get it Zanuck talked him into signing an eight-picture deal with 20th Century-Fox.
Darryl F. Zanuck was heavily involved in all aspects of the production, as he saw it as a personal project. In fact, so meticulous and carefully thought-through was his editing of Nunnally Johnson's screenplay that Johnson himself praised Zanuck for his attention to detail.
John Ford unmercifully chewed out Frank Darien for overemoting in the scene where Ma is preparing a simple stew for the family in front of a crowd of starving children in the migrant camp. By the time Ford had finished his tirade, Darien was completely drained, which proved to be exactly the take Ford wanted for the scene.
Far from being a leftist with an interest in social problems, John Ford decided to focus on the story purely through the Joad family as characters. "I was sympathetic to people like the Joads, and contributed a lot of money to them, but I was not interested in Grapes as a social study."
Much of The Grapes of Wrath was shot on the Twentieth Century-Fox lot, but second unit director Otto Brower took a crew to Oklahoma, Arizona, Texas, and New Mexico, following the route that the "Okies" had taken West. Additional locations included Needles, Daggett and Tehachapi, California. Brower and his crew filmed doubles in long shot to represent the Joad family members. Reportedly this same unit paid five dollars apiece to carloads of people actually making the trek to California to be filmed along with the Joad truck as part of the film's fictional caravan of migrants.
Darryl F. Zanuck's interest in sound reportedly led him to send a sufficiently loaded replica of the Joad truck to Oklahoma to record the grinding and shifting of gears. Sound effects editor Robert Parrish insists the audio footage was never used, and that Zanuck, thinking it was his requested sound of the truck that he heard in the rough cut, approved the soundtrack and never knew the difference.
John Ford treated Dorris Bowdon quite badly. It may have been because she was the girlfriend of screenwriter Nunnally Johnson and was given the part by Darryl F. Zanuck, or it may simply have been one of Ford's frequent unexplainable dislikes, but he hounded the young actress on every point, from coming on the set with her hair improperly done to taking time to have her hair fixed. Shortly before filming the scene of the dance at the government camp, Jane Darwell expressed her nervousness to Bowdon about "being such a fat old lady and I have to dance and say lines at the same time." When Darwell did the entire take perfectly, Bowdon spontaneously broke into applause, launching a tirade from Ford that made her run from the set crying. The next shooting day, Ford rather awkwardly cheered her up with a little bawdy humor, and the two got on well after that, although she later said, "I was glad I never had to work with him again." Yet, Bowdon in later life also expressed the duality of feelings actors often had for the difficult director when she related a story about how he painstakingly talked her through a very emotional moment that she ended up nailing in a single take. "He was a superb director," she said. "I never saw another director work in a way that was as skilled."
According to Henry Fonda, John Ford preferred only one take and little or no rehearsal to catch the most spontaneous moment. For the key climactic final scene between Tom and Ma, Ford didn't even watch the rehearsal. When the time came to shoot, Ford led Fonda and Darwell through the silent action of the scene, preventing them from starting their lines until the two actors were completely in the moment. It was done in a single take and Fonda said on screen it was "brilliant."
In the crucial scene between Tom and Ma, Henry Fonda had to strike a match whose light would illuminate Jane Darwell's sleeping face. Gregg Toland rigged a tiny light in Fonda's palm to achieve the effect.
John Ford's chief source of irritation was his inability to embarrass or upset John Carradine. According to Dorris Bowdon, Carradine had a huge ego, considered himself a great actor, and was impervious to whatever Ford threw at him, although their antagonism often produced perfect moments of performance and character.
Production began only four weeks after John Ford finished work on Drums Along the Mohawk (1939). Because of this, most of the pre-production work was done for him ahead of time, including the hiring of Gregg Toland as cinematographer, who along with art directors Richard Day and Mark-Lee Kirk planned much of the look of the film based on a vast array of research photos and documents.
Archived files indicate the area around Needles was used as a riverbank in the film, Canejo Ranch stood in for the Keene ranch, the Irvine Ranch in Tustin provided backdrops for a montage sequence, and Lasky Mesa, in the San Fernando Valley near Chatsworth, was used for the Joad farm and for Muley's farm. The real-life government-run Arvin Federal Government Camp near Bakersfield, California, was also used for some shots of the fictional government camp in the movie (e.g., the camp post office was used as the manager's office in the film).
Reportedly, Darryl F. Zanuck' was the one who had cricket chirps added to the soundtrack during the scene in which Casy and his "radical" associates are camped near the river, and he also is said to have insisted on the inclusion of a prominent accordion part in the spare musical score because he considered it the most American instrument. Although officially uncredited, sources list the accordion player as Danny Borzage, brother of director Frank Borzage and a regular bit player in Ford's stock company in a number of films between 1924 and 1964.
The trivia item below may give away important plot points.
The novel's original ending was far too controversial to be even considered for a film in 1940. It involved Rose-of-Sharon Rivers (Dorris Bowdon) giving birth to a stillborn baby and then offering her milk-filled breasts to a starving man, dying in a barn.