In chapter five of his book, "Searching For Black Confederates", Kevin Levin cites a supposed memo by then-Sons of Confederate Veterans commander Dean Boggs. Levin characterizes the remarks by Boggs as the genesis of the "black Confederate myth" that turned "camp slaves" into soldiers. In that memo is referenced a book to be written by Francis Springer, and stories from SCV members about the actions of black men supporting the Confederate States are solicited. I decided to see if any such book was ever written. In fact there was a book published thirteen years after Boggs supposedly solicited stories from the membership, but it's not exactly a smoking gun.
The book that Springer wrote is entitled "War for What?", and it was published in 1990. It is 221 pages and 30 chapters. It details the causes of the Civil War, gives a short history of the war itself, and briefly discusses Reconstruction. Black Southerners who supported the South are given one chapter out of thirty and a few paragraphs in other chapters. It is most definitely not a black Confederate manifesto.
Here are some of the quotes from Francis Springer's book that do pertain to "black Confederates". The claims here do not line up with the narrative Levin says the SCV created and pushed, particularly the first quote from page 104:
There were no Negro troops authorized by the Confederate government until almost the last few days of the war, and only one company found its way into combat. - p 104
General Pat Cleburne in 1864, urged the arming of the slaves, but it is hard to see how it could have been done effectively. The problem was logistics. Lee, with a line so thin that he couldn't spare men for a reserve, could not feed the men he had. Such food as there was couldn't reach the front because transportation had broken down. Still, some aver that armed slaves could have staved off the fall of Atlanta, and that peace negotiations then in progress might have ended favorably to the South. Maybe so. No one knows. - p 105
... the experiment of training Negro soldiers was tried in the South in March 1865. In the only documented occasion of Negro soldiers as such in combat, a company from Richmond hospitals "behaved in an extraordinary suitable manner" in defending the city a couple of weeks before the break through that forced the evacuation of Richmond. Many individual Negroes did serve as soldiers and were active in combat. Some were under fire while acting in other capacities. Some were in the Confederate Navy. Many Negro "body servants" accompanied their masters to the front, foraged for them, cooked, patched their uniforms, nursed them when sick or wounded, and buried them when they died. It was not the same thing as serving in units composed entirely of Negroes where all the qualities that make up unit efficiency could be tested, but it proved the individual qualities of those who went.... - pp 105-106
What was the attitude of Southern Negroes? Were they united in purpose, and what was their purpose? Most comments in print assume that all of them were waiting with hands uplifted in piteous plea for the Yankees who had sold them into their horrible conditions to come back and take them away from customers who had bought them. It will be no news to those who have studied the facts that this is nonsense, and certainly no news to anyone that all Negroes did not think, act and look alike. They were individuals, had their own class system and their lives were affected by many influences, especially by the attitudes of people white and black around them. - p 87
All Southern Negroes were not hoeing tobacco or picking cotton. Some were overseers, many were skilled craftsmen. Many were personal servants in families where a division of sympathies existed and would hear both sides of current political issues. Some were city dwellers, some free farmers, some (perhaps as many as 3,000 or more) were slaveholders. It is only natural that their attitudes would vary, but the South was the only home that most Negroes knew... - p 88