The only Amos Tacy who fits your criteria lived in Chateauguay, Franklin County, NY in 1880. He was born in Canada in 1825. His wife was Sophy also born in Canada in 1821. With them were two sons: Gilbert born 1857 and Philip born 1859, both born in Canada. In nearby Ellenburg, Clinton County was Israel born 1851 in Canada and working as a hired man. I can't find Amos or Sophy in 1900. Philip was married to Ellenand Gilbert was living with them in Hanover, Grafton County, NH. Israel was still in Ellenburg and married to Delia. They has 7 children. The census record says Israel immigrated to the USA in 1870. Does this sound like them?