In the scene in which Paul Robeson sings "Ah Still Suits Me", Queenie (Hattie McDaniel) has a box of Aunt Jemima pancake mix on her work table. It's a subtle nod to Tess Gardella (stage name "Aunt Jemima"), who created the role of Queenie in the 1927 Broadway production.
Special permission had to be granted from the Hays Office in order to retain the famous "miscegenation" sequence in the film. Miscegenation was banned as a film subject and the scene had been excluded from the 1929 film version.
Several scenes were cut before release, because they presumably would have made the film much too long (films lasting two hours or longer were still a rarity in 1936). Among the scenes omitted were a sequence featuring Paul Robeson and Hattie McDaniel in old-age makeup, with Robeson singing an additional reprise of "Ol' Man River" while McDaniel sits beside him in a rocking chair and a modern speedboat is seen in the background; a World War I scene featuring Irene Dunne and Charles Winninger, and a vocal reprise of "Gallivantin' Around", one of the additional songs written by Jerome Kern and Oscar Hammerstein II for the 1936 film version. This last one would have been part of the movie's final sequence in which Kim (played as an adult by Sunnie O'Dea) makes her debut in a leading role on Broadway. She was supposed to have sung the song in addition to dancing to it. The vocal of "Gallivantin' Around" was eventually cut from this final sequence, but much of the rest of the scene remains in the film, except for a "modern" portion which shows how dancing evolved from the nineteenth century to the jazz era.
As of 2010, there still has been no official soundtrack album made from the film. The songs sung by Allan Jones have been released on another album devoted exclusively to Jones, and the film's soundtrack was once issued on LP, on an obscure label called Xeno, but it did not receive the kind of remastered official CD or LP release accorded to such film soundtracks as The Wizard of Oz (1939), Gone with the Wind (1939) or the classic Disney films.
The design of the show boat is true to what a real show boat of that era might have looked like. This is partly because Jerome Kern and Oscar Hammerstein II wished it that way in their original stage instructions for the play, partly because of Edna Ferber's concern for historical accuracy, and partly because of director James Whale's sense of period design.
Universal Pictures' head Carl Laemmle was ousted from the company just after this film was completed. He retired from the business the day after its release, as did his 28-year-old son, who never produced another film.
Because of copyright problems involving a real "Cotton Blossom" show boat sailing the Mississippi in the 1930's, the name of the showboat in the film had to be changed to "Cotton Palace". This required omitting the second half of the opening chorus, in which the townspeople sing about the boat while the stevedores continue singing about their daily work, and the "cotton blossom" growing on the levee. The section sung by the stevedores is still heard in the film.
The scenes of the townspeople running toward the dock to greet the arrival of the show boat incorporate footage from the 1929 part-talkie film version. The moment in which this footage is used is very noticeable: for a few seconds, the image looks "speeded up", the way silent films used to look when shown on sound film projectors.
Although this film version of "Show Boat" was quite faithful to the show, and although it features many of the songs from the stage version, poster advertising for the film prominently mentioned the three additional songs written by Kern and Hammerstein especially for the film, even to the point of downplaying the fact that nine songs from the stage score were sung in the film, several of those were reprised twice or more, and three other songs from the stage version were used as background music.
Irene Dunne was thirty-seven years old (soon to turn thirty-eight) when she played the youthful Magnolia, although many biographies once listed her as being thirty-two at the time. Allan Jones, her love interest, was eight years younger.
The cost of production for the movie was more than Universal Studios could afford. Head of the studio, Carl Laemmle Jr., had to borrow money to finish the picture and to keep the studio afloat. When he reneged on an agreement to repay the loan, Universal Studios was taken over by a New York City lending institution. Laemmle Jr. lost his position at the studio his father had started and never again worked in Hollywood.
The songs "Why Do I Love You?", as sung by Irene Dunne and Allan Jones and the chorus "Happy The Day" (from the Act I Finale) were filmed but deleted before release, because it was felt that the movie was too long. Although "Queenie's Ballyhoo' had been sung in the prologue to the 1929 film version by Tess Gardella', it was not intended to be in the 1936 film version, where it would have had to be sung by Hattie McDaniel. "Life Upon The Wicked Stage" was also never filmed, and contrary to some claims, would not have been sung by Queenie Smith and Sammy White, but by Queenie Smith and a women's chorus. (Only the 1951 film version had Ellie - played by Marge Champion- and Frank - played by Gower Champion - singing the song.) The song "Why Do I Love You?" was to be sung in the scene in which Magnolia and Ravenal are riding in an automobile with their baby daughter, Kim. The rest of the scene remains in the film.
The first choice to play Ellie May Chipley in this film was Eva Puck, who had played that part in Show Boat's original Broadway run opposite her husband Sammy White as Frank Schultz. However, by the time this film was made, Puck was divorced from White, casting White was given precedence over casting Puck, and Queenie Smith replaced Puck as Ellie May Chipley.
The "Lux Radio Theatre" version of this film was broadcast on June 24, 1940, and starred Irene Dunne, Allan Jones and Charles Winninger from the film's cast. The radio version avoided all mention of racial issues by having "Ol' Man River" sung as a background choral number at the beginning, instead of as a number for Paul Robeson and male chorus. It also changed Julie from a mulatto illegally married to a white man to an illegal alien whose husband chose to be deported with her.