John Henry "Doc" Holliday (August 14, 1851 – November 8, 1887) was an American gambler, gunfighter, and dentist of the American Old West who is most well-known for his friendship with Wyatt Earp and his involvement in the Gunfight at the O.K. Corral.
As a young man, Holliday earned a D.D.S. degree from the Pennsylvania College of Dental Surgery and set up a dental practice in Atlanta, Georgia. In 1873, he was diagnosed with tuberculosis, the same disease that had claimed his mother when he was 15. He moved to the American Southwest in hopes that the climate would prolong his life. Taking up gambling as a profession, he subsequently acquired a reputation as a deadly gunman. During his travels, he met and became a good friend of Wyatt Earp and his brothers. In 1880, he followed the Earps to Tombstone, Arizona and took part in the Gunfight at the O.K. Corral.
After Virgil Earp was maimed by hidden assailants and Morgan Earp was murdered, Holliday joined Deputy U.S. Marshal Wyatt Earp's posse in the Earp Vendetta Ride, during which they killed four outlaw cowboys. The members of the federal posse were indicted by the Tucson courts for killing Frank Stilwell. No longer welcome in the state, the posse members rode to New Mexico and later Colorado. Wyatt Earp learned of an extradition request for Holliday and arranged for Colorado Governor Frederick Walker Pitkin to deny Holliday's extradition. Holliday spent the remaining few years of life in Colorado and died in his bed at a hotel in Glenwood Springs, Colorado, at the age of 36.
Holiday's colorful life and character has been depicted in many books and portrayed by well-known actors in numerous movies and television series. Since his death, researchers have concluded that Holliday killed from three to seven men and was present at nine shootouts