Sorry it took so long to answer this. Somehow I missed the posting. My records show that Crenshaw Parkman was Henry Parkman Sr's youngest son (1760-1820). I have no support for this but since Henry's wife's maiden name was Crenshaw it makes sense. I did a lot of research on Henry's parentage, and made what I think is a breakthrough in that area. Please comtact me if you are interested.