Billy the Kid was one of the most notorious outlaws of the American West. Born William Bonney in New York City in 1859, Billy spent his childhood in Kansas, Colorado, and New Mexico. At the age of 12, he is said to have committed his first murder when he stabbed a man who had insulted his mother. In his teen years, Billy turned to a life of robbery and violence. By age 18, he had committed perhaps a dozen more killings.

In 1877 Billy became a cowhand on a ranch in New Mexico. The following year, a "war" broke out between two cattle-ranching families. Billy became a leader of one of the rival gangs and played an active role in many bloody gun battles.

In April 1878, Billy was one of a group of men who gunned down the local sheriff, James Brady, and a deputy. The governor of the territory offered Billy a pardon if he surrendered. The outlaw refused and continued with his life of violence and lawlessness. He led a gang of...