cebtoo on Family Tree Circles

1860 census shows he was from Canada, but subsequently census shows from Ireland. He married Susan Hydorn who apparently owned a farm at Depeyster, St. Lawrence, New York. He is listed in the Alien registration book in St Lawrence County as having arrived in 1856 during a period when immigrants flowed freely through Canada and on into United States. There were at least three Alexander Blairs in and around St. Lawrence County mid 19th century. He is buried in Hillcrest Cemetery, Heuvelton, NY with several family members including his first wife Susan Hydron (whose grave marker has the misspelling "Hydron". He is documented in the book "Hydorn, Nelson, York Lineages of St. Lawrence County". Where did he come from?