Thanks Greg. I bought the book, but most of the information reported by the author takes place around Tullahoma (coincidently NOT because that is the name of his first book) and Nashville. Reviewing the bibliography, there is mention of two Union Provost Marshal files in the National Archives. Now I recall that he said these records were not organized by time line, geography or any other rational order. Guess that answers my own question. A person would have to travel to Washington and spend hours looking at microfilm.