If you haven't read it, The History of a Brigade of South Carolinians, by J.F.J. Caldwell and available in full view on google books, is a must read. Toward the end, those fellows were leaving bloody footprints in the snow, because some of them didn't have shoes!

A trip to Pamplin Park should be in order, also. It is only open every now and again, due to budget cuts, but the earthworks built by McGowan's brigade (your ancestor) still remain. The house where the officers slept and where the book was written is also in the park.

Your ancestor served for 4 long years and more than likely, unless in the hospital or on furlough, took part in the Gettysburg campaign and was fighing in the Bloody Angle at Spottsylvania.