Despite winning an Oscar for his direction, Elia Kazan revealed in a later interview that he was never fond of this movie, feeling that it lacked passion on his part and he thought that the romance was too forced.
When other studio chiefs, who were mostly Jewish, heard about the making of this film, they asked the producer not to make it. They feared its theme of anti-Semitism would simply stir up a hornet's nest about a problem which they preferred to handle quietly. Not only did production continue, but a scene was subsequently included that mirrored that confrontation.
The movie mentions three real people well-known for their racism and anti-Semitism at the time: Sen. Theodore Bilbo (D-Mississippi), who advocated sending all African-Americans back to Africa; Rep. John Rankin (D-Mississippi), who called columnist Walter Winchell "the little kike" on the floor of the House of Representatives; and leader of "Share Our Wealth" and "Christian Nationalist Crusade" Gerald L.K. Smith, who tried legal means to prevent Twentieth Century-Fox from showing the movie in Tulsa. He lost the case, but then sued Fox for $1,000,000. The case was thrown out of court in 1951.
The timeliness of the film is revealed by a telling exchange that took place between screenwriter Moss Hart and a stagehand, as reported in "The Saturday Review", December 6, 1947, pg. 71: "You know," a stagehand is reported to have said to Mr. Hart, "I've loved working on this picture of yours. Usually I play gin-rummy with the boys when scenes are being shot. But not this time. This time I couldn't leave the set. The picture has such a wonderful moral I didn't want to miss it". "Really?" beamed Mr. Hart, pleased not only as a scenarist but as a reformer. "That's fine. What's the moral as you see it?". "Well, I tell you," replied the stagehand. "Henceforth I'm always going to be good to Jewish people because you never can tell when they will turn out to be Gentiles."
Laura Z. Hobson wrote her novel after vitriolic ant-Semitic comments by Mississippi Senator John Rankin were applauded on he floor of Congress. The novel was then serialized in "Cosmopolitan" magazine from November 1946 to February 1947, immediately causing quite a stir. This prompted Fox studio boss Darryl F. Zanuck (one of the few studio heads who was not Jewish) to snap up the novel's rights.
In 1984 Gregory Peck claimed to have been misquoted in a 1967 interview in which he said Elia Kazan was the wrong director for the film. The actor said, "That's a misunderstanding. I don't think there could have been a better director for the film. What I meant was that he and I didn't have a rapport; emotionally, we were not on the same wave length. I don't think that I did my best work for him. If I worked with him now -- as a mature man -- I think I would give him everything he would want".
The role of Phillip Green was first offered to Cary Grant, but he turned it down. Grant refused the role because he contended he was Jewish and thought he looked Jewish. He maintained, "The public won't believe my portrayal of a gentile trying to pass himself off as a Jew."
Many were concerned that this film would somehow lend credence to the bizarre belief among the political right that "Jewish-friendly" films and novels from the time were inspired by communism, or were intentionally made as Communist propaganda. That fear was legitimized somewhat when many of the people involved with the film were brought before the House Un-American Activities Committee (HUAC) -- which was tasked with uncovering "Communist subversion" in the entertainment industry -- including Darryl F. Zanuck, Anne Revere, (perhaps most notoriously) Elia Kazan and John Garfield. Garfield was brought before HUAC twice, was blacklisted, taken off the blacklist and put back on it again; it was believed that the stress of these experiences led to the heart attack that killed him at the age of 39.
In September 1948, the film was rejected for showing in Spain. The New York Times reported that the ban was instigated "by order of the ecclesiastical member of the Film Censorship Board on moral grounds. According to a source close to the board, the banning order stipulated that while it was a Christian duty to 'stimulate love among individuals, societies, nations and peoples,' this should not extend to Jews." The report listed six points or "theological errors" of the film that warranted the ban, including that the film declared "that a Christian is not superior to a Jew" and that the film asserts that "for many Jews it is a matter of pride to be called Jews. Pride of what? The pride of being the people who put God to death? Of being perfidious, as they are called in Holy Scripture?" On October 3, 1948, according to Hollywood Reporter, the President of the Board of Film Censors in Madrid, Gabriel Garcia Espina, called the statement reported in New York Times to be a "calumny" and that the film was, in fact, banned because anti-Semitism was not an issue in Spain. Espina stated, "There is no racial problem in Spain. We do not know here the conflict of Semitism or anti-Semitism. And precisely because of the beautiful and traditional Spanish idea of human freedom, these anguishing racial differences that have disturbed so much, and apparently do disturb, the lives of the peoples, are alien to us and we want them to continue being alien to us." The film, however, was approved for showing in Spain on January 12, 1949 under the title La Barrera Invisible.
Dialogue in the film refers to a number of then-prominent demagogic figures known for their bigotry, including U.S. Senator Theodore Gilmore Bilbo, from Mississippi, who advocated deporting all African Americans to Africa; Representative John E. Rankin, also from Mississippi, who in a statement from the House floor called broadcaster and columnist Walter Winchell "the little kike"; and Gerald L. K. Smith, a Christian Nationalist Crusade leader. In May 1947, Darryl F. Zanuck queried Fox legal counsel George Wasson on whether they were breaking any laws by making the references. After Wasson responded that no court would consider the references a violation of "right to privacy," and that there was only a slight risk of libel, Zanuck wrote, "Let them sue us. They won't dare and if they do nothing would make me more happy than to appear personally as a witness or a defendant at the trial." In April 1948, Smith did sue Twentieth Century-Fox in a Tulsa court to ban the film in Tulsa, his home for the previous six months. After a district judge refused to issue a restraining order, Smith took his complaint through the court system, suing the company for $1,000,000, but in February 1951, the case was dismissed.
In the scene where Phil (Gregory Peck) goes to check on his mother Mrs. Green (Anne Revere) after she suffers a mild heart attack, she says, "No need to look like Hamlet, I feel wonderful." "Gentleman's Agreement" won the Best Picture Oscar of 1947, and Sir Laurence Olivier's "Hamlet" won the Best Picture Oscar of 1948.
Phil Green's middle name in the film was Schuyler, although early in the film he is known as Schuyler Green. This came up in jocular conversation when Green attended a dinner party at the Minifys' house. John Minify: "What do people call a guy whose name is Schuyler?" Phil Green: "Phil". John Minify: "Good, then I don't have to say 'Green' all the time. Too hard the last name and Schuyler is impossible. I wouldn't call a dog Schuyler". Coincidentally, Schuyler happens to be the middle name of Celeste Holm's third husband, A. Schuyler Dunning, whom she married in 1946.