Long simmering tensions in Lincoln County, New Mexico, explode into a bloody shooting war when gunmen murder the English rancher John Tunstall.

Tunstall had established a large ranching operation in Lincoln County two years earlier in 1876, stepping into the middle of a dangerous political and economic rivalry for control of the region. Two Irish-Americans, J.J. Dolan and L.G. Murphy, operated a general store called The House, which controlled access to lucrative beef contracts with the government. The big ranchers, led by John Chisum and Alexander McSween, didn’t believe merchants should dominate the beef markets and began to challenge The House.

Tunstall, a wealthy young English emigrant, soon realized that his interests were with Chisum and McSween in this conflict, and he became a leader of the anti-House forces. He won Dolan’s and Murphy’s lasting enmity by establishing a competing general merchandise store in Lincoln. By 1877, the power struggle was threatening to become overtly violent, and Tunstall began to hire young gunmen for protection, including the soon-to-be-infamous William Bonney, better known as Billy the Kid.

Early the next year, The House used its considerable political resources to strike back at Tunstall, winning a court order demanding that Tunstall turn over some of his horses to pay an outstanding debt. When Tunstall refused to turn over the horses, the House-controlled Lincoln County sheriff dispatched a posse-with William Morton, another House supporter, at the head-to take them. Billy the Kid and several other Tunstall hands were working on the ranch when they spotted the approaching posse. Outnumbered, the men fled, but they had not gone far before they saw Tunstall gallop straight up to the posse to protest its presence on his property. As Billy and the others watched, Morton pulled his gun and shot Tunstall dead with a bullet to the head.

Although he had not worked for Tunstall long, Billy the Kid deeply resented this cold-blooded murder, and he immediately began a vendetta of violence against The House and its allies. Lincoln County became a war zone, and both sides began a spree of vicious killings. By July, The House was prevailing, having added McSween to its lists of victims. However, fighting would continue to erupt sporadically until 1884, when Chisum died of natural causes, and The House finally regained full control of Lincoln County. By that time, Billy the Kid had already been dead for three years, gunned down by Lincoln County Sheriff Pat Garrett.