The real Wyatt Earp's six-shooter was loaned by the Earp museum and used in some scenes during a number of close-ups.
Gene Hackman receives third billing and is named on all posters, although he has less than ten minutes of screen time.
Wyatt Earp had seven siblings: James, Virgil, Martha, Morgan, Baxter Warren, Virginia, and Adelia; also, an elder half-brother, Newton, from his father's first marriage.
Kevin Costner commandeered every western costume in Hollywood for this film, forcing rival production Tombstone (1993) to import costumes from Europe.
Jim Wilson: Film's producer appears as Virgil Earp's doctor. Wilson also appeared as a doctor in Dances with Wolves (1990).