Gunfights and general lawlessness were common in the frontier cities of the American West. Tombstone and Dodge City are legendary. But neither saw violence approaching that of Los Angeles in the 1850s.In his Reminiscences of a Ranger, Horace Bell reports that ""midnight raids and open day robbery and assassinations of defenseless or unsuspecting Americans were of almost daily occurrence"" in southern California, a territory newly acquired from Mexico. To combat this lawlessness, in 1853 the citizens of Los Angeles formed a volunteer mounted police force known as the Los Angeles Rangers. Under the command of Captain Alexander Hope, the Rangers strove to keep the peace within the city, and they hunted down bandits and murderers in the surrounding region, including several connected with Joaquin Murrieta's band.

The life of a mounted ranger appealed to Horace Bell, a civilian who later became an attorney and ran a newspaper. As John Boessenecker says in the introduction to the book, Bell's memoir is a history of early Los Angeles, an essential and highly entertaining source for this period of the California Gold Rush. With a sharp eye for detail, Bell sketches numerous pioneers, politicians, military figures, and outlaws, and he vividly describes riots and shootouts in the city streets and campaigns against Indians and bandits.