The Kentucky Derby archival footage was the actual 1955 race, won by Swaps, who played "Glory" in the film (Willie Shoemaker up), over over Nashua (Eddie Arcaro up).
Glory (1956) was not the movie comeback hit that 19-year-old Margaret O'Brien needed after being away from the screen since 1952. Part of the problem was that the film was nothing new. There was the predictable romance where the plain but sweet girl wins the rich boy with the spoiled fiancée, and there is really little doubt whether or not the horse will win. This picture also failed to garner a contemporary New York Times review, the fate shared by her previous vehicle, Her First Romance (1951).
In 1957, Walter Brennan and Madge Blake would be reunited on the television series The Real McCoys (1957).
Half-way through Glory (1956), there are some musical numbers, with Margaret O'Brien being dubbed by Norma Zimmer, who would be much better known for her 22 years as The Champagne Lady with bandleader Lawrence Welk.
Arthur Hunnicutt was originally cast as "Ned Otis," but he quit the production after arguments with producer-director David Butler over "the way the role of a horse trainer should be interpreted."