A Goggle search leads to these hits:

http://books.google.com/books?id=g1klLhyYmN8C&pg=PA49&lpg=PA49&dq=J.W.+Minnich&source=bl&ots=zbxUkt0cF1&sig=zT0kmjN_1vDfUi88yNzg0JwyhJE&hl=en&ei=QL7LSpCrBIrIsQP498ShAQ&sa=X&oi=book_result&ct=result&resnum=2#v=onepage&q=J.W.%20Minnich&f=false

http://openlibrary.org/b/OL7011389M/Inside_of_Rock_Island_Prison

http://books.google.com/books?id=HsrhBfiB0RsC&pg=PA14&lpg=PA14&dq=J.W.+Minnich&source=bl&ots=vTUJbqpmwu&sig=UMkfVSwFXdrsR-JBVru8IsWdxlY&hl=en&ei=9r7LSryWIoL6sQPplsyVAQ&sa=X&oi=book_result&ct=result&resnum=4#v=onepage&q=J.W.%20Minnich&f=false

http://www.illinoiscivilwar.org/riarsenal.html

John W. Minich, Pvt. Company G, 6th Georgia Cavalry's cards are filed with George W. Minich

George W. Minich enlisted as a Private in Company G, 6th Georgia Cavalry August 18, 1861, at Abington, Virginia, captured January 27 at Pigeon River, Tennessee, 1864, sent to Camp Chase, Ohio February 4, 1864, sent to Rock Island, Illinois February 15, 1865, paroled and released on taking the Oath June 18, 1865, age 21