Though shot in Technicolor, the film incorporates actual black-and-white footage of Seabiscuit in races, including the 1940 Santa Anita Handicap and the 1938 match race against rival War Admiral, which is still considered by many to be the greatest horse race of all time.
The film was mostly shot at Northridge Farms. This facility was established by Barbara Stanwyck and Zeppo Marx. It was also filmed at Burns Park, Santa Anita and Burns Ranch in Woodland Hills, California.
In 1940, an RKO film project variously called Blood Will Tell and True to Form had a cast including Lucille Ball, Edna May Oliver with first Dick Powell in the lead, then at various times John Wayne, Randolph Scott and James Craig. Technicolor footage of Seabiscuit was recorded, including his win at Santa Anita against Kayak after he had recovered from a ruptured suspensory ligament. Eventually, the film project was scrapped but David Butler revived the idea years later and Têmpera de Vencedora (1949) came about.