Some years ago the History Channel aired a program call "40 acres of Hell, Fort Douglas" or something like that. They made the comment in that program that black confederate soldiers captured at the Battle of Arkansas Post were not allowed to enter the POW camp with the white soldiers. They were shot outside the Camp.
What is interesting is that Jasper McKowan is listed as being of Company "I" 19th Arkansas Inf., IF that was Dawson's 19th Arkansas Infantry, Jasper would have been captured at Arkansas Post because It was part of Dunnington's Brigade in the Fort itself.
Was Jasper McKowan one of the black Confederate soldier shot by Union guards outside Camp Douglas?
Also someone might do some research into the Sons of Confederate Veterans membership records as there are several at present African American members of that originations