Thank you both. I'm still puzzled because the Dodges came to Massachusettes from England before 1640. In the 1790 census, Caleb Dodge was at 25 mile pond plantation (later Burnham, Waldo, Maine). He was back at 25 mile pond plantation in 1820. The number and distribution of people in the census are similar enough to hint that this is the same person (and I haven't found him anywhere else so I think it is reasonable that it is the same person) so I don't know when he would have been living in Londonderry, NH, either. It is a mystery. I'd love to hear any more theories, and I do appreciate the NH one too. Thanks.