Here’s someone I found in the World War I draft cards: Robert A. Pryor Prior (see below), a pitcher for the St. Louis Giants, the Louisville White Sox, and three A.B.C.’s teams, 1914-17.  He appears in Riley (p. 643) and The Negro Leagues Book (p. 216) without a first name.

In the Indianapolis Freeman (June 17, 1916) he is referred to as “Pryor, the big colored southpaw,” though the draft card lists his height and build as both “medium.”

UPDATE 4:01 p.m.  Unbelievably, I only just now noticed that he signed his name “Prior,” with an “i,” on the card.  Which, by the way, raises a point about these draft cards: I believe that standard procedure in many places was for the examiner to fill the card out, while the registrant only signed it at the end.  In many, many cases (and I think this is one of them, though isn’t an especially dramatic case) the handwriting on the form does not match that on the signature line; and though I’m not a handwriting expert, it doesn’t seem to be merely a matter of a person’s signature hand being somewhat different from his regular hand.