Dear Allan
Welcome to Ireland Reaching Out!
As you can see from the link below, Seagoe is a Civil Parish in north east Armagh:
http://www.irishtimes.com/ancestor/fuses/townlands/index.cfm?fuseaction=TownlandsInCivil&civilparishid=400&civilparish=Seagoe&citycounty=Armagh
Church of Ireland records for the parish begin in 1683 until 1865 for baptisms and 1713 until 1753 for marriages. In between there are a lot of gaps in the series. Records for the corresponding Roman Catholic Parish of Seagoe or Derrymacash begin in 1836.
It would be a good idea to check family search or roots Ireland websites to see if there are any records in relation to your ancestors:
www.familysearch.org has a huge database of genealogical records including some church records for Ireland.
www.rootsireland.ie have a large collection of Irish Church records, however you have to pay to use this site.
There are 4 marriage records on rootsireland for example, for a James O?Brien married to a wife, first name Mary.
Other important sources include the Tithe Applotment Books and Griffith?s Valuation. Even though these sources only record the head of the household, the information is very important and can be valuable:
Tithe Applotment Books (1823-1837): http://titheapplotmentbooks.nationalarchives.ie/search/tab/index.jsp
Griffith?s Valuation (1847-1864): http://www.askaboutireland.ie/griffith-valuation/
The National Archives of Ireland: http://www.census.nationalarchives.ie/search/ you can search the 1901/1911 Census on the National Archives page too, for instances of the family name at that time
Remember to post any new information that you find here. The more information you post, the more likely it is that one of our volunteers will be able to advise or assist you. Also include information concerning which sources you may have already used so others may further your search.
Best of luck with your search
Clare Doyle
Genealogy Support