I have Richardsons from New Portland in my family info. I am descended from Sally Richardson born in New Portland in 1791. She was the daughter of Ebenezer Richardson and Jerusha Dodge. I have quite a bit of info on the Richardson family. Sally had two brothers, Ebenezer and Daniel. It is quite possible that one of them would be the father of your William. Do you know the date of Williams birth by any chance?