He and Ben Springer were the co-owners of the successful Lady Gay Dance Hall and Saloon in Dodge City, which employed the popular singer Dora Hand.

At that time Charlie Bassett was the Marshal, having replaced Jim's brother Ed, who was killed in the line of duty two months earlier.

In the summer of 1878, a cowboy named George Hoy opened fire on the Comique Variety Hall, outside of which stood Masterson and Wyatt Earp.

He made several hundred arrests during the next two year time span, mostly of drunken cowboys who came through Dodge City on cattle drives.

On April 6, 1881, he lost his job after a change in city government, and the belief that the long-standing hard-line stance of the Marshal's Office was past its prime and no longer useful.

Peacock, over the hiring of the latter's brother-in-law, Al Updegraph, as bartender, and someone wired Bat Masterson in Tombstone that his brother's life was in danger.