Eugene Cunningham (1896–1957)

In this now classic volume, Eugene Cunningham collects―in his “gallery” ―biographies of nearly a score of master gunfighters, including such notables as John Wesley Hardin, Billy the Kid, Dallas Stoudenmire, Sam Bass, Wild Bill Hickok, Butch Cassidy, and Tom Horn. Himself a Westerner familiar with the feel of pistol and rifle, Cunningham knew firsthand several of the Texas gunfighters featured in his book, the product of more than thirty-five years of research, interviews, and writing.

the wit and writing is dated, generally, but is quite the fun read. My copy is the third printing of the first edition and is in wonderful shape. There is a fun and excellent summary at the end on 'slapping leather'.