At the beginning of each episode they state that this is an actual story from the pages of the Tombstone Epitaph but at the end of every episode they state that any resemblance to any character, living or dead, is coincidental.
At the beginning of each episode, the narrator claims each is "An actual account from the pages of my newspaper, the Tombstone Epitaph." While the Epitaph was an actual newspaper in Tombstone circa 1881, the series is hit or miss for actual events- and characters. For example, the actual Territorial Governor John C. Fremont is mentioned in the pilot, however, Clay Hollister is referred to as Sheriff of Tombstone. Tombstone by late 1881 was in newly-formed Cochise County, so Hollister would have been called Sheriff of Cochise County. The actual Sheriff of Cochise County in late 1881 was Johnny Behan. Tombstone had a city marshal at the time, Virgil Earp. While Curly Bill Brocius, an actual person, appeared in the pilot (dated August 6, 1881) and two other episodes, no mention is made of the Earp family, who had resided in Tombstone since 1879. The third episode, dated November 1, 1881, was less than a week after the famous October 26, 1881 OK Corral shootout involving the Earps with Doc Holliday against Ike Clanton, Billy Claiborne, Tom and Frank McLaury, and Billy Clanton, yet no mention is made of this significant event.
Hollister wears two guns which is something Hollywood made up, no man in the old west wore two guns.