you mentioned great-grandmother was Sarah Dumas DeBerry - There is a family of Dumas' in Charleston that is well known - they run Dumas Clothing Store on King Street, known for upscale casual men's clothing. Their family I believe originally had roots in Berkeley County (possibly as peddlers). You might check with them for a connection. There were twins, JOE and ABE, but it believe they are both deceased, however I think the sons or grandchildren still run the store.