The O.K. Corral fight scene was highly accurate - but much of the rest of the movie was typical Hollywood hyperbole. Read Casey Tefertiller's excellent biography "Wyatt Earp - the Life of a Legend" for a somewhat different picture of how things went - chiefly, that the Cowboys had more backers in town than the Earps, who after the shootout were considered the villains and had to essentially flee for their lives. Also, the scene at the end of Tombstone where Doc kills Johnny Ringo is sheer Hollywood invention - no one knows how Ringo died.
I still like the movie - it just isn't too realistic. I guess Hollywood thinks the real story is boring, since they've never told it correctly. ;)
The events leading up to the gunfight, the shooting of Virgil and Morgan, and Wyatt's vengeful tracking down of the Cowboy killers are all historically correct. Yes, they made up the fight between Ringo and Doc Holliday, but I accept that as dramatic license and there is, after all, somewhat of a mystery as to who really did kill Johnny Ringo.
One interesting aspect of the Earp-Clanton struggle that no movie has ever covered is the political dimension. The Earps were midwestern, Union Republicans while the Clanton cowboys were ex-Confederate Democrats. That set-up bad blood from the beginning and in fact, made their feud a mirror-image of the general fault lines in early territorial politics.
"no one knows how Ringo died."
At least the movie had him dying at the base of a tree with a head wound. The last theory I read was that the guy who found the body and apparently knew Ringo may have shot him as he slept.
Isn't "Johnny Ringo" fictitious?