Doc Holliday was an enigmatic character. Despite his raucous ways as a known gambler and drinker, in “Doc Holliday: The Life and Legend,” author Gary L. Roberts points out that Holliday was brought up as a “Southern gentleman” in Georgia. After becoming a dentist, he moved West, where he befriended legendary lawman Wyatt Earp. He developed tuberculosis at a young age, which drove him to the dry Arizona climate.

Kilmer used this as a launching point for developing the Holliday character. “The main spine starts with the fact that the Southern aristocrat and his entire world had just been blown up and disappeared forever as if it had never existed,” Kilmer said in a 2017 interview with Deadline.

Beyond that, Kilmer had what he considered to be a secret weapon in his acting arsenal. Kilmer said:

“I started with my secret weapon, the dialect and speech coach Tim Monich who works with the best people on earth, 24/7 for 30 years now. I told him I needed a dialect that didn’t exist anymore and within days, there was a tape at my doorstep of a true Southern aristocrat who spoke so slowly and precisely about the theater he had restored.”

Kilmer took what was on that tape and used it to shape the entire Doc Holliday character.