The Abraham Lincoln Library in Springfield, IL has Civil War CDVs by regiment. The photographs can be reviewed and the library (for a fee) will make a copy. Also, their are photos of 5 men from 112 IL INF on the Illinois in the Civil War or The Illinois in the Civil War Project website. The United States Military History Institute at Carlisle Barracks in PA has a large collections of Civil War photographs that can be research by name and/regimental number. They will send you a photocopy from which you can order a photograph.