A quick comment regarding the Rank In and Rank Out question...

The records were organized by unit, in this case a battalion. 'Rank In' is supposed to be his rank at the time of enlistment. 'Rank Out' is supposed to be his rank when he was discharged. In reality, 'Rank In' is the first surviving record showing rank of a man in a unit and 'Rank Out' is the last surviving record in that unit. If he was in multiple units, there would be separate records for each unit with 'rank in' and 'rank out'. Men changed units for a variety of reasons, e.g. enlistment ran out, separated from their unit by illness, reorganizations, didn't like their unit and ran off and joined another. Their rank could change up or down for a variety of reasons too.