Answer:
The legal action against McSween and the violence that followed was a result of the takeover of the Tunstall-McSweeny store and the killing of John Tunstall. (The warring factions in every way sought to protect their business interests.)
Step-by-step explanation:
The war in Lincoln County has taken place since 1878 and continued until 1881. It was a conflict between two powerful, opposing business factions at the time. James Dolan managed the monopoly of goods through the trade. Alexander McSween and John Tunstall opened a competitive store, and that's how the rivalry came about. Both sides brought together teams of attorneys and business associates to gain market dominance.
However, the situation is compounded when persons from the criminal milieu are recruited to one side and the other. The conflict was marked by revenge killings, beginning with the murder of Tunstall by members of the Evans gang. In retaliation for that, regulators killed Sheriff Brady. The situation culminated in a five-day confrontation on the streets of Lincoln where Mcsween was eliminated. This event also inspired Hollywood itself, based on which several films were made.