Before the rise of professional academic history, there were devoted Brahmins of a literary bent (George Bancroft, Francis Parkman and Henry Adams) and skilled researchers and chroniclers, men such as J. Thomas Scharf of Maryland history fame and - the most prolific of all - Ben Lossing of New York, who, since they made their living by writing history, could rightly be labelled professional after all. Every literate history lover in the mid-to-late...