"The Book of Dow" has a John Dow who m. Mary McCrillis. They had a daughter Philena b. 1821.The book traces John back to immigrant Henry who came to Watertown MA in 1637. The line has a couple of places where there appears to be some "educated guesswork." If you are interested in more detailed information, let me know. Although there may be questions in the line, possibly the information could provide clues that would enable you to either verify it or discount it.