Scott,

Thanks for quick response. I found Charles Rosenhauer in the NPS Civil War data base showing:

Regiment Name:Sappers and Miners, Missouri Volunteers (3 months, 1861)
Side:Union:
Company:A
Soldier's Rank In:Prv. 2 Cl.
Soldier's Rank Out:Private
Alternate name:
Film Number:M390 roll 41
Notes:
Plaque Number:

And as you said,

2nd Regiment, US Reserve Corps, Missouri Infantry
Side:Union:
Company:G
Soldier's Rank In:Private
Soldier's Rank Out:Private
Alternate name:
Film Number:M390 roll 41

Charles had a brother, Edward, who also served in the USRC but in a different Company.

There is a Charles Rosenhauer listed in Missouri records for the Enrolled Missouri Militia and he is shown as a deserter. Probably the same man. Could it be that he was thought to have deserted but actually enlisted in the Reserve Corps? Lastly, since Chas' name shows up in the NPS info does that mean his service was Federal?

Thanks again,

David