The line quoted by Doc at the end of the fight at the OK Corral is historically true and was reported in the Tombstone papers reporting the fight. When confronted by one of the Cowboys at point blank range, the Cowboy reportedly said, "I got you now Doc, you son of a bitch," to which Doc gleefully retorted, "You're a daisy if you do!"
When the Earps first enter Tombstone, a grave marker can be seen in the cemetery that reads "Here lies Lester Moore, Four slugs from a .44, No Les No more." There is an actual tombstone in Tombstone, Arizona that has that epitaph.
Although the gunfight at the O. K. Corral plays out more or less as it did in real life, the filmmakers made several small changes. In the actual incident it was Ike Clanton who ran through the corral to escape (in the film it is Barnes who runs out the back). The film instead shows Ike Clanton running into the photographer's studio while firing a few shots back at the Earps and Doc. In reality, it was Billy Claiborne who performed this action before escaping unscathed.
Robert Mitchum was signed on to star as Old Man Clanton. On the first day of shooting he fell from his horse and injured his back, forcing him to quit the part, which was then eliminated from the film. Instead, Mitchum provides the narration at the beginning and end of the film.
Kevin Jarre began as director, filming all of Charlton Heston's scenes. After he was fired, Kurt Russell rallied the cast and crew to continue shooting, for fear that the studio would shut the picture down instead of hiring a new director.
At the Birdcage Theater, one of the cowboys sees the juggler, "Professor Gilman" and says "Aw! Professor Gilman? I seen him in Bisbee. He catches things." To which another cowboy stands up, pulls a gun and says "Hey, Professor! Catch this!" and shoots one of the bowling pins he's juggling. This is based on a true anecdote told in the Time Life book series "The Old West-Gunfighters" profile of the OK Corral shootout. As in real life, the juggler raced off stage yelling "My God! They're really shooting at us!" Actually...."Professor" Gillam was performing a show in which blanks would be fired at him, and he would spit slugs out of his mouth that he had already prepared, when the cowboy made his "Catch this" remark.
Here is the translation of what Doc and Johnny Ringo are saying to one another in Latin: Doc Holliday: In vino veritas. (In wine there is truth.) Johnny Ringo: Age quod agis. (Do what you do.) Doc Holliday: Credat Judaeus Apella, non ego. (Let Apella the Jew believe, not I.) Johnny Ringo: Iuventus stultorum magister. (Youth is the teacher of fools.) Doc Holliday: In pace requiescat. (May he rest in peace.) The line "Credat Judaeus Apella, non ego. (Let Apella the Jew believe, not I)" was confusing to viewers; scholarly papers showed that Romans used the phrase to show contempt for Judaism's belief that divine power was involved in everyday life.
The expression "I'm your huckleberry" spoken by Doc means "I'm the perfect man for the job." It could indeed be a reference to Mark Twain's Huckleberry Finn, then known as the sidekick of Tom Sawyer before Huck got his own book.
Val Kilmer has been quoted as saying that screenwriter Kevin Jarre insisted the actors wear real wool costumes, in accordance with the time period. In the Birdcage Theater scene, Val Kilmer says, a thermometer was placed on the set, and it read 134 degrees Fahrenheit. Kilmer suggested jokingly that this was the reason Doc Holliday killed so many people: "It's just, like, he wore wool in the summer, in the Arizona territory, and that made him mad."
Just before the "Gunfight at the O.K. Corral" sequence, Josie is fleetingly seen inside Fly's Photographic Studio posing for the now famous (and authenticity-disputed) photograph, "Kaloma." The almost nude lady in this photograph is not really Josephine Marcus in Tombstone, but instead seems to be an East Coast showgirl from 1913 or 1914, based on the copyright date on the photo itself.
Kevin Jarre's original script for Tombstone was significantly longer than the final film. It was intended to be an epic, detailing the lives of all the combatant parties in the story. After Jarre was fired as director, George P. Cosmatos hired John Fasano to trim the script to focus primarily on the Earp family (to make the already-delayed shoot more manageable). Fasano received co-author credit in early promotional materials, but his name was removed from the film's credits (probably due to Writer Guild arbitration). Instead, Fasano was given an Associate Producer credit.
Just prior to the O.K. Corral fight, Wyatt Earp is seen taking a Colt peacemaker with an unusually long 10 inch barrel and an engraved plaque inlaid in the grip from a presentation case. Such a weapon has long been associated with the legend of Wyatt Earp, probably stemming from the story that dime novelist Ned Buntline ordered several such guns from Colt, and gave them to the peace officers of Dodge City as gifts. In spite of the popularity of this story there is no credible documentation that Wyatt Earp ever owned or used such a "Buntline special." Most credible accounts agree that on the day of the infamous shootout Wyatt Earp was armed with a Smith and Wesson model 1869 break top style revolver of the same type that Virgil Earp is seen using in the movie.
Many scenes/subplots cut from the film still did not make the expanded DVD version: one sequence was the Cowboys' bonfire rally/mourning scene, which takes place the night they buried the OK Corral dead. A brief shot can be seen in some of the trailers (Curly Bill throwing a bottle of whiskey into the bonfire).
The Latin phrases spoken by Doc and Ringo have implied meaning beyond their literal translation. The conversation could be translated into English this way: DOC: In wine there is truth. RINGO: Do what you do best. DOC: The Jew Apella might believe it, but not I. (from Horace's Satires, book 1, satire 5, lines 100-101) RINGO: (tapping his gun) Youth is the teacher of fools. DOC: May he rest in peace. (from Edgar Allan Poe's The Cask of Amontillado).
When Wyatt is at the train station standing on the loading platform, giving Ike Clanton his "you tell em' I'm comin', and hells comin' with me" speech, really going crazy on Ike, he's standing in front of train car #5150 (the California police code for a crazy person).
Before being sheriff of Cochise County (Tombstone), Democrat John H. Behan (1844-1912) had previously served as sheriff of Yavapai County (Prescott)from 1871-1873. Virgil W. Earp (1843-1905) was nominated as the Republican candidate for sheriff of Yavapai County in 1900. He subsequently withdrew for health reasons.
The trivia items below may give away important plot points.
As extraordinary as the scene in which Wyatt kills Curly Bill Brocius in the creek is, it is true. During the shootout in the creek when Wyatt kills Curly Bill, the next person he shoots is Johnny Barnes (the cowboy who yells "JESUS CHRIST!!"). As in real life, Wyatt shoots Barnes in the stomach. However, Barnes was not killed on site. He managed to escape and died in a farmhouse. However, before dying, he told the story of how Wyatt REALLY did walk into a hail of Curly Bill's gunfire unscathed, walked right up to Bill and shot him point blank with both barrels of a double-barreled shotgun.
I'll be damned" really are the final words of John "Doc" Holliday. To this day, historians have debated on why Doc said that. The main theory is that Doc had become a gunfighter hoping that someone would kill him and spare him the effects of tuberculosis and that he was amazed that the disease is what killed him: not the drinking, gambling, or gunfighting.
In the movie, Curly Bill Brocius is not charged with the murder of Marshal Fred White as there were no witnesses to the shooting. In real life, charges were not filed because prior to his death, Marshal White explained the shooting was an accident.