On this day, May 10, in 1875, former slave Bass Reeves was sworn in as a deputy U.S. Marshal in Fort Smith, Ark., becoming one of the most feared and fearless lawmen in the Old West.

Reeves was hired by “the Hanging Judge,” Isaac Parker, to help bring justice to the vast Indian Territory, a haven for outlaws. Reeves was an expert with pistol and rifle, spoke several Indian languages and was familiar with the Indian Territory in what is now Oklahoma.