Black Southerners in Confederate Armies: A collection of historical accounts
Virginia's Black Confederates: Essays and Rosters of Civil War Virginia's Black Confederates
In the case of the books you cite, southern partisans whose agenda is to redeem the moral stain that adheres to the confederate cause by digging up random bits and holding them up to say, "See, it really wasn't about slavery! Look, here's a black guy who got a confederate pension!"
HK Edgerton here was a friend of mine , one upon a time
https://www.youtube.com/watch?v=lp3pRiw9aQk
DV