I finally got to see the lecture, and have to ask how many officers in Cleburne's Division actually got to see the memorandum, and other than those who signed it, how many did not agree/sign/or have an opinion either way? We may never know.
The disturbing thing coming out of the lecture (speaking about the Confederate side) is that there was strong talk in letters, of "conditions" set to "control" the Black/labor population after the war. Again, (speaking of the South) after the war there was a war of terror, (KKK comes to mind) used to keep blacks, and their sympathizers from gaining political control. (Jim Crow Laws coming later)
Seems they were somewhat successful in "Controlling" the Black population, in spite of what the North, and the Freedman's Bureau were trying to force on the ex-Confederacy. (Again, I speak of what the SOUTH was doing)
Having said that, I’m STILL of the mind that the Southern leadership used Secession, to keep their slavery system well in hand, and were of no mind to let the “Black Republican Party” interfere. Firing on Ft. Sumter was an act to stop any interference.
The South was not of the mind to get rid of slavery during the secession crisis, and only to do so in some degree (with limitations) when they realized the they were up against overwhelming odds.
The URL I have below is letters of differing opinions sent to R.E. Lee about arming slaves. These letters are from Howell Cobb, and Samuel Clayton