Billy the Kid (1859–1881), a notorious gunfighter of the Old West. A swaggering, cold-blooded killer to some, a romantic young firebrand to others, he was a legend in the Southwest even before his death at the age of 21. According to tradition, Billy killed 21 men, "one for every year in his life." Actually he probably was involved in not more than nine killings.

Billy the Kid was born Henry McCarty in New York City. He later used aliases derived from his stepfather's name, William Henry Antrim. Eventually, he was known as William H. Bonney and nicknamed Billy the Kid. Billy spent his boyhood in Indiana, Kansas, and New Mexico. He got into trouble with the law in 1875, when he was caught stealing. In 1877 he killed for the first time, in Silver City, New Mexico.

In the Lincoln County War (1878–81), a bloody range war in New Mexico, Billy killed several men, including Sheriff William Brady. Billy was captured by Sheriff Pat Garrett in December, 1880, and convicted of Brady's murder. He was sentenced to death but escaped from jail in March, 1881, killing two deputies. He was tracked down and killed by Garrett in July, in Fort Sumner, New Mexico.