[citation needed] Some time around 1874 Peppin became The first person with James Dolan, a partner to Lawrence Murphy in a local mercantile and banking operation.

[1] By 1876, rancher and businessman John Tunstall had partnered with Alexander McSween to form a rival business, which developed into tensions between the Murphy-Dolan and Tunstall-McSween factions.

On February 18, 1878, John Tunstall was shot and killed, officially while resisting arrest, by Lincoln County Deputies William Morton, Jesse Evans, and Tom Hill.

[3] In what would become known as the Battle of Lincoln, Peppin and his posse well outnumbered the besieged Regulators, and received assistance from the US Cavalry under the command of Colonel Nathan Dudley.

[citation needed] Peppin lived in fear following the range wars end, resigning as sheriff immediately afterward, and begging for sanctuary at Fort Stanton, where for a time he worked as a butcher.