Was your ancestor a North Carolina soldier, or did his regiment serve at some point in North Carolina? This UNC-Chapel Hill online exhibit may be of interest:
"Images in the North Carolina Collection depicting the war are from woodcuts, engravings, lithographs, and photographs. The overwhelming majority of these were made by persons accompanying Union forces or were made from sketches and other information they provided."
If you find any images of special interest, you can get a high-quality photo print of those images:
"Low resolution digital images included with the Civil War Portfolio are provided for reference purposes only. Information on obtaining copies and conditions for using them is available from the North Carolina Collection's Photographic Archivist. Black-and-white photographic prints in sizes from 5 x 7 inches to 20 x 24 inches may be purchased as well as high resolution digital copies and color transparencies."
Interested? Go here: LINK