"RE: Berlin's figures, Chapter 5, Table 6, subtract the 84,000 free Blacks in Maryland, the 20,000 in Deleware and the 11,000 in the District of Columbia- which were not part of the Confederacy- from your "southern" total and tell me what you get."

Greg, Berlin's totals were for free blacks in the South, NOT merely the Confederacy. I'm sure you are aware that there were slave states in the Union, just as there were Southerners who were both pro-slavery and pro-union (up until secession and war, anyway).

The blacks most likely to support the Confederacy were often of mixed race. In cities such as Charleston and New Orleans, this population represented an elite, and existed (tenuously, at times) between enslaved blacks and the dominant white population. Why did they support the Confederacy? Out of fear, to a certain degree, but often to support their own self-interest. Many were themselves slaveholders, after all.

There was a debate in the South about emancipation. I'm sure you are aware of that. The internal contradictions of the CSA - was the primary issue white supremacy or independence? - undermined the efforts of some Confederates to achieve this 'revolution from the top'.

Greg, you and some others here seem to have misunderstood me completely. I am not a neo-Confederate or an apologist. I have not argued here (or anywhere else) that large numbers of blacks fought for the Confederacy (this should be clear from previous posts).
But some did support the CSA, and it is worthwhile to try to understand why they did so. That is ALL I am saying.

I'll look up the petition of some Charleston free blacks volunteering for military service and post it here. It illustrates my points about race and class among so-called 'Black Confederates'.

PS Re: secession - I think you and I would both agree that while secessionist tendencies go back far before 1860 and involve issues other than abolition, it was the slavery debate that brought first South Carolina and then other slave states to leave the Union.