You might want to start with the Allegany naturalization records. They are filmed by the Family History Library and looks like they start in 1866. If your ancestor filed a petition for citizenship, it might say what year he emigrated. You never know till you look. I am attempting to locate information on my father's ancestors John & Mary > O'Brien > who started their family in the rural community of Birdsall in Allegany > County, New York > sometime prior to 1840. > > According to the 1850 US Census John was born in 1795 in Ireland and Mary > was born 1805. > Their first child, Abigail, was born in 1839. Their other children > included: > Ellen (1841), > Catharine (1843), and Michael (1849) > > -- Pat Connors, Sacramento CA http://www.connorsgenealogy.com