For the film The Kid From Texas, the star role of Billy the Kid was portrayed by a war hero. His name was Audie Murphy.

 Audie Murphy was awarded 33 U.S. military medals, including three Purple Hearts and one Medal of Honor. He was the most decorated soldier from WW2.
After proving himself in battle during an invasion at Sicily Murphy was promoted to Corporal. During another battle in France, Murphy’s closest friend was killed. Corporal Murphy charged and killed the Germans that had just killed his friend. The corporal was not done. He commandeered a German machine gun and grenades and attacked several more nearby positions and killed all of the Nazis in the area. Mr. Murphy was awarded the Distinguished Service Cross for his actions and was only 21 years old at the end of the war. By the end of it, he alone had killed 240 Nazi soldiers and had been wounded three times.

When Murphy returned to the USA in summer of 1945, he was greeted as a hero. Parades and many fancy banquet dinners were set to honor Murphy.
LIFE magazine honored the brave, smooth faced soldier by putting him on the cover of its July 16, 1945 issue.
The photo prompted actor James Cagney to call Murphy and invite him to Hollywood to start his career in showbiz. Leading to his role as Billy the Kid.

Universal Studios began Filming in 1948 on locations at the Jack Garner Ranch in The San Bernardino National Forest, Idyllwild and Universal Studios at Universal City, California.
The film stars Audie Murphy as Billy the Kid, Frank Wilcox as Pat Garrett, Robert Barrett as Governor Lew Wallace, Albert Decker as Kain(Mcsween), Sheppeard Strudwick as Jameson(Tunstall) and Paul Ford as Sheriff Copeland.
The Kid From Texas is loaded with shoot-em-up action based on real historical events.
Like all Billy movies the facts are fictionalized with a few twists from the movie makers, but stick to the basics. The battle in Lincoln and the escape from the burning Mcsween home, offer another view on how Mcsween dies…
FBI founder and director J. Edgar Hoover was a big fan of Murphy and offered to narrate the film, but Parley Baer was selected instead. (good choice)