Thanks so much for getting back to us with this wonderful information, you have been able to get quite far back in time!
The name Killough
is a rare surname and seems to be most prevalent in County Antrim, with Ballymoney
being the most popular for the families.
Before 1864 records were kept in the form of church and parish records, all the surviving records have been sorted into county-based genealogical centres
. In 1864 civil registration was introduced in Ireland, which is when we started seeing the formal registration of births, marriages, adoptions, and deaths. These records have been kept at the General Register
Office of Ireland (GRO), through the Irish Genealogy website, to this day. Records for Northern Ireland would be found here until 1921 when GRONI was set up.
The Ulster Historical Foundation
runs a webpage that may be of interest. It has some pay-per-view records so please check it out if you feel it would be helpful.
Hopefully, you can find some additional information about your family here.