Patricia, the man's name is Henry Senn, but his service record doesn't provide any clues as to his age, where he lived, etc. I've never been able to find him in the 1860 census of any Arkansas counties.
He was recruited by Co. D, 24th Arkansas Infantry, but never served with the company. Part of the regiment was captured at Arkansas Post on January 11, 1863, and by the time Henry Senn was mustered into service at Warren, Arkansas, on February 1, 1863, the Arkansas Post men were on their way to Union POW camps in the north. The uncaptured portions of the 19th and 24th Arkansas Regiments were organized into Hardy's Arkansas Regiment, and Private Senn was assigned to Co. C of the new regiment. He apparently served with this command for the rest of the war.
I know that other Louisiana men, including some from Union Parish, served in Arkansas regiments, and, since Henry Senn doesn't seem to be listed in the Arkansas census, my assumption is that he is the man listed in the 1860 census of Union Parish, Louisiana -- I just can't prove it. Yet.