Little is known about Billy the Kid’s early days, but he was most likely born Henry McCarty in the Irish slums of New York City sometime in late 1859. Raised by a single mother, he moved to Wichita, Kansas, as a boy before later migrating west to New Mexico in the early 1870s. Henry quickly adapted to life in the rugged territory and became fluent in Spanish, but his sickly mother died of tuberculosis in 1874, leaving him an orphan at the age of just 14. Left in the care of an absentee stepfather, the future gunslinger spent the next year living in foster homes and boarding houses. Before long, he fell in with a rough crowd and turned to petty crime and thievery.

Henry McCarty’s first run-in with the law came in 1875 when he assisted a local street tough known as “Sombrero Jack” in stealing clothing from a Chinese laundry. Henry hid the loot in his boarding house but was arrested after his landlord turned him in to the sheriff. The crime only carried a minor sentence, but rather than face punishment, the wiry youth escaped the jailhouse by shimmying up a chimney. McCarty then fled town and embarked on a career as a roving ranch hand, gambler and gang member. He became handy with a Winchester rifle and a Colt revolver, and in August 1877 he killed his first man during a dispute in an Arizona saloon. That same year, he adopted the alias “William H. Bonney” and became known as “Billy the Kid” or simply “The Kid.”

Billy the Kid first earned his reputation as a gunslinger in 1878, when he participated in a bloody frontier war in Lincoln County, New Mexico. The conflict centered on a business rivalry between British-born rancher John Tunstall and a pair of Irish tycoons named James Dolan and Lawrence Murphy. Dolan and Murphy’s outfit—known as “The House”—had long held a monopoly over the dry goods and cattle trades in Lincoln County. When they tried to intimidate Tunstall’s upstart operation, the Englishman enlisted the Kid and several other gunmen to protect his property. The tensions finally boiled over in February 1878, when Tunstall was murdered by a posse organized by Sheriff William Brady, a supporter of The House.

Following Tunstall’s death, the Kid and several other former employees organized themselves into a vigilante group called “The Regulators” and swore revenge. In what became known as the “Lincoln County War,” the Regulators assassinated Sheriff Brady and spent the next several months shooting it out with The House’s forces. In July 1878, the feud reached its climax with a deadly, five-day firefight in the town of Lincoln, after which the Regulators disbanded and the two sides sealed a flimsy peace agreement. The Kid left the war with a reputation as one of the West’s most skilled gunmen, but he remained wanted for the murder of Sheriff Brady. He would spend the rest of his life on the run from the authorities.

Unlike other Old West outlaws such as Jesse James, Cole Younger or Butch Cassidy, Billy the Kid didn’t make his living as a bandit. The young gunslinger stole the occasional horse, but he never once held up a bank, train or even a stagecoach. Outside of his gunfighting days with the Regulators, his main criminal enterprise was rustling cattle on the New Mexico plains.

The Kid was known for his easygoing personality, but he wasn’t afraid to draw his six-shooter when provoked. In a four-year span between 1877 and 1881, the baby-faced outlaw was involved in the shooting deaths of some nine men, at least four of whom he killed singlehandedly. One particularly legendary gunfight unfolded in January 1880 at a New Mexico saloon. As the story goes, a drunk named Joe Grant was terrorizing the bar’s patrons and threatening to kill someone before the night was out. Sensing trouble, the Kid casually approached Grant and remarked, “That’s a mighty nice-looking six-shooter you got.” He then slipped Grant’s gun out of its holster, spun its cylinder so that its next shot would be an empty chamber, and handed it back. It proved to be a wise move. Later that evening, Grant pulled the same pistol on the Kid and tried to shoot him in the back. When it didn’t fire, the Kid drew his own gun and shot Grant dead.

In late 1880, Lincoln County Sheriff Pat Garrett tracked the Kid to a cabin in Stinking Springs, New Mexico, and forced his surrender. The outlaw was found guilty of the murder of Sheriff William Brady and confined to the Lincoln courthouse. He was scheduled for a date with the hangman, but on the evening of April 28, 1881, he engineered the most daring getaway of his criminal career.

During a trip to the outhouse, the Kid slipped out of his handcuffs, ambushed a guard and shot the man to death with his own pistol. He then armed himself with a double-barreled shotgun and gunned down a second guard who was crossing the street. Once in control of the courthouse, the Kid collected a small arsenal of weapons, cut his leg shackles with a pickaxe and fled town on a stolen horse. News of the brazen escape was soon reprinted in newspapers across the country, making the Kid the most wanted man in the West.

After his escape from death row, the Kid spent several months hiding out on the frontier and taking refuge with sympathetic locals in Fort Sumner, New Mexico. He neglected to keep a low profile, however, and it wasn’t long before Sheriff Pat Garrett and two deputies rode into town. On the night of July 14, 1881, Garrett went to the home of rancher Peter Maxwell to question him about the outlaw’s whereabouts. No sooner had he woken Maxwell than the Kid also approached the house, having stopped nearby to get beef for a late dinner.

When he noticed the silhouette of one of Garrett’s deputies on the porch, the Kid drew his pistol and backed toward the door, shouting, “Who’s that?” in Spanish. As he entered Maxwell’s darkened bedroom, he spotted the shadowy outline of Garrett and once again asked, “Who’s that?” Upon recognizing the Kid’s voice, Sheriff Garrett drew his six-shooter and fired off two rounds in his direction. One bullet struck the 21-year-old near his heart, killing him instantly.

Pat Garrett became an Old West legend for killing Billy the Kid, yet as the years passed, rumors circulated that the Sheriff had either shot the wrong man or helped fake the outlaw’s death. In the late 1940s, an elderly Texas man known as “Brushy Bill” Roberts even claimed to be Billy the Kid in the flesh, but his story was largely discredited after family records revealed his birthdate to be 1879. Other investigators have since theorized that the Kid lived to be an old man under the alias “John Miller.” Miller’s alleged remains were exhumed in 2005, but a plan to compare his DNA to the Kid’s never materialized. Despite the controversy, historical records show that the Kid’s body was positively identified by several different people the day after his shooting, leading most historians to conclude that Sheriff Garrett got the right man.

The Kid was a celebrity in his own time, but his legend only grew after his death thanks to dime novels, television shows and Hollywood films. Beginning with the 1911 silent film “Billy the Kid,” the gun-toting outlaw’s story has appeared on the big screen more than 50 times. Some of the most famous actors to play the Kid include Roy Rogers, Paul Newman, Val Kilmer and Emilio Estevez.