The American Social History Project/Center for Media and Learning at the City University of New York Graduate Center will host a two-week NEH Summer Institute for college and university faculty in July 2018 on the Visual Culture of the American Civil War and Its Aftermath. Applications to participate will be accepted via mail, e-mail, and our online application system until March 1, 2018.
H-CivWar is H-Net's network on scholarship, teaching, and outreach on the history of the American Civil War.
Forgive my immodesty, but I dealt with this topic in my article that appeared in the September 1996 issue of _Civil War History_ -- "'We Cannot Treat Negroes . . . as Prisoners of War': Racial Atrocities and Reprisals in Civil War Arkansas." That piece can also be found in my edited volume, _Black Flag over Dixie: Racial Atrocities and Reprisals in the Civil War_ (Carbondale: Southern Illinois University Press, 2004), which contains several related essays.
I know a gentleman who has done a lot of research regarding this issue. I will pass your interest along to him and perhaps he can assist you. Of course, if he is willing, arrangements will have to be made for you both to communicate.
I assume you have read Andrew Ward, The Slaves' War and of course Been In The Storm. There are also 2 or 3 new books about the 54th and 55th regiments. Arieivpro@aol.com