1. The Tunstall Faction:
- Led by John Tunstall, a wealthy English rancher and businessman.
- Included Billy the Kid, Dick Brewer, Charlie Bowdre, and other cowboys working for the Tunstall ranch.
- Also supported by some local ranchers and businessmen who opposed the Dolan-Riley faction's monopoly on the county's cattle industry.
2. The Dolan-Riley Faction:
- Led by James Dolan and Alexander McSween, prominent businessmen and political figures in Lincoln County.
- Supported by Sheriff William Brady and his deputies, as well as some local ranchers and outlaws.
- Sought to control the lucrative cattle trade in the county and eliminate their rivals, including Tunstall and his faction.