I am trying to to trace origin of my Duffy ancestors, James and Ann Duffy born around 1800 and their children Patrick (1829), Anthony (1831), Mary (1836), James (1838), Thomas (1841) and Ann (1843) all born in Ireland. They appear on the Huddersfield, Yorkshire 1851 census lodging with another Duffy family, James and Bridget (né Kingsley) Duffy, probably relatives, who had arrived in Huddersfield before 1840. My Grandmother always said they were from Sligo near the Mayo borders. I'd be grateful for any information on either family. Nothing in any census or church record in the UK or US (to where some finally emigrated) nor marriage certificates has so far shed any light as to their birthplace.