John: I've researched ex-slaves in the USCI a few years ago. Found three men who served from St. Francois and Washington counties in Mo. but they are a difficult lot to locate and research. The three I mention were located accidentally. Two of them did not survive the War but I believe all were from the 56th USCI. Quite a bit in the OR on the USCT. In several years of postings in Civil War publications I could never find but one person who was interested in this branch of the service.