Dear Archie, I am replying to the email you sent to the Co. Tyrone website. Researching in Ireland before 1800 is really difficult. If your ancestor had a child in 1785 he must have been born in at least 1760. You don’t say whether that was in Ireland or USA. I would suggest that you search our community website http://cotyroneireland.com/ for the name O’Hagen which may give you some idea of the prevalence of that surname in Co. Tyrone. Otherwise I believe you could search the Archives of this mailing list through Rootsweb to see if anyone else is searching for this surname. Best I could do unfortunately. Margaret in Oz.