John Henry Holliday (August 14, 1851 – November 8, 1887), better known as Doc Holliday, was an American dentist, gambler, and gunfighter who was a close friend and associate of lawman Wyatt Earp. Holliday is best known for his role in the events surrounding and his participation in the gunfight at the O.K. Corral in Tombstone, Arizona. He developed a reputation as having killed more than a dozen men in various altercations, but modern researchers have concluded that, contrary to popular myth-making, Holliday killed only between one and three men. Holliday's colorful life and character have been depicted in many books and portrayed by well-known actors in numerous movies and television series.
At age 20, Holliday earned a degree in dentistry from the Pennsylvania College of Dental Surgery. He set up practice in Griffin, Georgia, but he was soon diagnosed with tuberculosis, the same disease that killed his mother when he was 15 and his sister before his birth, having acquired it while tending to his mother's needs.