And now it turns out he wasn't just the provost marshal of Callaway County. In 1868 Isaac Snedicor was registrar of voters in Callaway County, and had to establish his wartime loyalist bona fides. In doing so he had to provide sworn answers to a list of questions, one of which is as follows--
Q. Were you during the war a Union man, and what did you do to prove your faith by your works?
A. I was a Union man emphatically. I was a provost marshal, under the United States government, of Callaway, Montgomery, and Audrain counties, and afterwards I was in the enrolled militia.
This statement shows up in 'Index to Miscellaneous Document of the House of Representatives for the Second Session of the Fortieth Congress, 1867-1868,' published 1868.