It is my understanding that, several years ago, the history department at Jackson State University (located in Jackson, MS) began working on the history of the Black Union regiments raised in MS. While I cannot confirm this research, it might be worth your while to try contacting said department at said university. At the very least, they might know of someone researching these units. There used to be a Black Federal Re-enactor unit in the Jackson area, but I haven't seen anything on them in a while. You might also try contacting the Fort Pike (Louisiana) State Historical Site, as there is a Black re-enacting unit that often appears there. Hope this helps! -- Jim Huffman, Gainesville Vols