If you have not already checked it out, you might want to look through Bill Brown's book Thoughts on Men's Shirts. As mentioned in a previous response, Chris Daley has done some work on US issue shirts, but you might also talk to Charlie Childs of County Cloth. Charlie sells a number of repro. shirts all based on original CW era Confed. shirts.
There are several CW period shirts in the Atlanta History Center collection, but most are without provenance. Bill Christensen also been researching mid 19th century civilian shirts.
To Join the Company of Military Historians click here