Re: henry LaFountain b 1871 /Lowell Mass/West Chazy NY
Looking through census records, I can only guess at connections.
In 1880 Champlain, NY Census: Henry, 12 years (b.NY) is living with brother Zeb and widowed mother Sophy.
In 1900 Champlain, NY Census: Henry (b.Nov-1869 MA) is married to Mary B, with children Avil, Arthur and Cora. He is living next to Zeb (b.Jul-1858 NY) and mother Sophia, widow.
In 1910 Chazy, NY Census: Henry (40 years, b.NY) with wife Alphonsine, children Eva, Arthur, Cora, Beatrice and Emma.
1920 Chazy, NY Census: Henry (50 years, b.MA) with wife Parry, children, Arthur and Emma.
1930 Chazy, NY Census: Henry (61, b.MA) with wife Alphonsine and daughter Emma Brown (spouse of Elmer Brown).
I looked for Sophy/Sophie/Sophia Lafountain in 1870 census but did not have any luck.He appears to flip-flop between birth in NY or MA, but the children and siblings give connection clues.