Wondering if you ever got an answer to your DOUGLASS / CONGDON question. I've read too that this couple was in Washington Co. at one point before being in Clinton Co. Curious as to why they were in Washington Co.
We have David CONGDON who was in Washington Co. from 1803 for sure and we thought he was in Clinton Co. in 1800 (from a census record. Just a few days ago I came across a deposition David made that he came to Fort Ann from Clarendon VT in 1793. I guess it's possible he left for a few years so that still could be him in Clinton Co. in 1800. Not sure.
There were two CONGDONs in Fort Ann (Westfield) in the 1790 Census John & Joseph. Is your Mercy connected to either of them? Have always wondered if there might be some sort of relationship with Mercy & David, but have not found any proof to that effect. They were however in same place or places around the same timeframe.
I'm now looking to learn more on John & Joseph from Fort Ann, and the CONGDONs who were in Clarendon VT in 1790. I'd be surprise if there isn't a connection to at least one of these men. The approach of working backwards after 20 years is getting old, so looking from different angles now!
If you have found additional info or have a David or unknown male CONGDON b. between 1772 - 1780 (this is our best guess for a birthdate), please let me know.
I believe we have a photo of Douglass CONGDON's grave from Clinton Co. Do you have that? Can't remember if there were other DOUGLASSes there with him or not.