Thomas Josiah Dimsdale, frequently referred to as "Prof. Thos. J. Dimsdale" or "Professor Dimsdale," claims a place in nineteenth-century western American literature on the strength of one book, The Vigilantes of Montana, or Popular Justice in the Rocky Mountains. Being a Correct and Impartial Narrative of the Chase, Trial, Capture and Execution of Henry Plummers Road Agent Band, together with Accounts of the Lives and Crimes of Many of the Robbers and Desperadoes, the Whole being Interspersed with Sketches of Life in the Mining Camps of the "Far West," published in 1866. It gives a detailed account of vigilante justice in the early settlement of Montana, and it has been a direct source for later writers, most notably Mark Twain in Roughing It (1872) and Ernest Haycox in Alder Gulch (1941). It strongly endorses popular justice and is an important early text in the debate about lynching that figures in later...