The working titles of this film were America, American Miracle, The Magic Land, This Is America and An American Story. According to modern sources, Man of Tomorrow was also a working title. The character of "Teddy Dangos," as played by Horace McNally, provides intermittent offscreen narration throughout the film. The picture also includes several documentary sequences depicting the manufacture of steel, cars and planes. According to a late Oct 1944 HR news item, the film was cut from 151 to 122 minutes after exhibitors complained about its length. It is possible that some of the above-listed actors were cut out for the shortened version. According to records in the M-G-M Music Collection, the hymn "Lord Please Send Down Your Love" was performed in the film by black singer Leon Warrick. Warrick is also listed in the CBCS, but the song was not heard in the viewed print and was apparently cut for the shortened version. (Modern sources note that director-producer King Vidor wrote the song's lyrics.)

       In his autobiography, Vidor related that he conceived of An American Romance, a picture that took him three years to complete, as the final part of his self-proclaimed "war, wheat, and steel" trilogy. "War" was represented by Vidor's 1925 epic The Big Parade (see AFI Catalog of Feature Films, 1921-30; F2.0405), and "wheat" by the 1934 independent production Our Daily Bread (see AFI Catalog of Feature Films, 1931-40; F3.3296). Vidor adds that at the time of the film's inception, he was considering joining the Army Air Corps motion-picture division, but finally concluded that making An American Romance, with its "arsenal-of-democracy" theme, would be the most effective way to serve his country.

       In a modern interview, Vidor stated that he got the film's basic story line from a series of stories and recollections by Yugoslavian-born Louis Adamic, who had worked in the Minnesota iron ore mines around the turn-of-the-century. Vidor was also influenced by the lives of American industrialists Andrew Carnegie, Charles Steinmetz, William Knudsen and Walter Chrysler, according to his autobiography. According to a modern source, in 1941, Vidor wrote a three-page outline for the film and sent it to Adamic, who then wrote the first few sequences of the picture. HR announced in Mar 1942 that Adamic was collaborating on the script with Vidor. Adamic's contribution to the completed film, if any, has not been confirmed, however. In the modern interview, Vidor stated that he used the town of Hibbing, MN, as the model for his screen town, although Hibbing was not specifically mentioned in the film. Modern sources note that from Jul 1941 to Apr 1942, many writers, including Norman Foster, John Fante, James Hill, Tom Treanor, Wessel Smitter, Ross B. Wills and Renata Oppenheimer, worked on drafts of the film's treatment. Smitter, Gordon Kahn, Frances Marion and Vincent Lawrence made minor contributions to the screenplay, which Vidor initially co-wrote with credited scenarist Herbert Dalmas. In Apr 1943, credited writer William Ludwig worked on a full rewrite of the script with Dalmas and Vidor. Robert D. Andrews contributed dialogue to the added scenes, which were shot in Nov 1943, according to modern sources.

       According to the modern interview, Vidor pitched the story of An American Romance directly to M-G-M vice-president and general manager Louis B. Mayer, who in turn told the story to M-G-M president Nicholas Schenck, who then gave the final go-ahead. Spencer Tracy was Vidor's first choice to play "Steve Dangos" and was announced as the film's star in Aug 1942. In his autobiography, Vidor comments that Tracy symbolized "all that the character of Stephan Danahos [sic] stood for." Because of scheduling conflicts, Vidor was forced to replace Tracy with Brian Donlevy. Vidor noted in the modern interview that he had hoped to cast Ingrid Bergman as Steve's wife and Joseph Cotten as "Howard Clinton," but both actors had previous commitments. HR reported in early 1943 that Ann Sothern and Frances Gifford were also under consideration for the female lead, and Philip Dorn, John Hodiak and John Craven were tested for top roles, but not cast. After a screen test, Vidor was persuaded to cast Australian newcomer Ann Richards (1917--2006), who reportedly came to America on the last boat to leave Australia after Pearl Harbor, as "Anna." According to HR, Richards, who had had small roles in three earlier M-G-M films, was not cast until after principal photography had begun in Apr 1943. HR news items add Richard Crane, Richard Derr and Edmond Breon to the cast, but their participation in the final film has not been confirmed. In addition, HR notes that Donlevy's six-week-old daughter Judith Ann was cast in the role of baby "Tina."

       In the modern interview, Vidor stated that certain aspects of the film's visuals were inspired by the paintings of American artist Charles Burchfield. Vidor claimed that he designed the film's color scheme to "follow the same progressive uplifting refinement" as its story line. A HR news item noted that paintings and sketches used in the film were created by the Society of Illustrations and were featured in the 2 Oct 1944 issue of Life magazine. According to Vidor's autobiography, miniatures were first used for the final bomber assembly line sequence. Upon viewing the completed scenes, however, Vidor declared that they looked "unreal in contrast to the rest of the film" and arranged to reshoot "in an honest-to-goodness factory, using the actual detailed construction of a Flying Fortress."

       According to Records of the War Department, Public Relations Division, dated 28 Sep 1942, Vidor requested and received permission to shoot footage at many different mines and factories in the Midwest, including the Ull-Rust mine in Hibbing, MN, the Duluth dock in Duluth, MN, and the Ford River A & O Rouge Plant in Dearborn, MI. 16mm background footage was shot at a blast furnace in Irontown, UT, according to the War Department records. HR notes that second unit atmospheric and background shots were taken at Lake Superior, MI. Scenes were also shot at two U.S. Steel Corporation subsidiaries--the Carnegie Illinois Steel Works in Chicago and the Indiana Steel Plant in Gary--as well as at the Chrysler auto factory in Detroit, the Douglas aircraft factory in Long Beach, CA, and the Consolidated plant in San Diego, CA. According to a HR news item, a steel mill in Hammond, IN, was also used as a location. The War Department records add that footage from an Army Air Force feature entitled Memphis Belle (See Entry) was to be used in the picture. According to an IP article about the film, other scenes were shot in the Mesabi Range, MN. In the modern interview, Vidor recalled that some exteriors were shot in Wilmington, CA, near Los Angeles, and that for those scenes, actor John Qualen doubled for Donlevy. Vidor also noted that footage was taken during the Indianapolis 500 car race and was used as background in the racing scene. War Department Records from Sep 1942 include a long list of scheduled second-unit crew members, including director Gunther V. Fritsch, but their participation in the completed film has not been confirmed.

       Prior to the film's 11 Oct 1944 world premiere in Cincinnati, Vidor, Donlevy, Richards, Walter Abel and Horace McNally dedicated An American Romance airplane in Dayton, OH, and participated in ten days of personal appearances and parades. In his autobiography, Vidor noted that after its Cincinnati premiere, M-G-M's New York office ordered that thirty minutes be cut from the film. Although Vidor expected the time to be taken out of the documentary sections, which he himself felt were too long, most of the cut footage came out of the dramatic scenes because the documentary sequences were already married to the music track. Modern sources and the modern interview note that the edited footage included a scene at the Indianapolis Speedway and a scene depicting a confrontation between Steve and his workers. Vidor recalled in the modern interview that head M-G-M editor Margaret Booth made the final edits. Despite some favorable reviews, the film, which cost almost three million dollars to make, did not do well at the box office. Displeasure over the studio's handling of An American Romance eventually led to Vidor's departure from M-G-M, the studio at which he had worked for twenty years, according to the modern interview. In Mar 1943, HR noted that the Museum of Modern Art in New York was using the film's production as a subject for an exhibit about the making of a motion picture. Scripts, research material, shooting schedules and inter-office memos were among the materials presented.