If the person for whom you seek military records was in a National Guard
regiment mustered into active duty in the GAR,
and mustered out in less than 90 days, an official record may not exist.
You may have to rely on the existence of
historical articles published by the media. Under these conditions they
probably didn't qualify for a pension or a land grant.
Example: Colonel Charles Somers Smith, Commander of PA National Guard
Infantry Regiment 1 (Gray Reserves).
Entire regiment mustered into GAR Infantry Regiment 32 to
assist in the defense of Harrisburg during the
Battle of Gettysburg. NARA has no record of the Colonel.
As far as I know, this is mentioned in only in a
PA genealogical history and in a history of the NG Regiment.
If anyone is interested in members of this
unit, I have some names and you can email me direct, since I
don't recall any CHAMPION listed.