Hi thanks for your message and interest in Ireland Reaching Out.
There are a number of sources that may help you with your search.
The Irishtimes website is a great website for those interested in researching their family tree. If you follow this link it will take you to the section pertaining to CO. Down.
http://www.irishtimes.com/ancestor/browse/counties/ulster/index_dn.htm#Down
On the left-hand side of this page is information on what kind of records are available for the county.
Since your great grandfather was born before the earliest official census the best place to look for information may be in Church Records.
If your Great Grandfather followed the Church of Ireland, the records are available here:
http://ireland.anglican.org/about/42 and http://www.nationalarchives.ie/.
If he was a Roman Catholic a list of what records are available can be found here:
http://www.irishtimes.com/ancestor/fuses/rcparishmaps/index.cfm?fuseaction=showidrecords&CityCounty=Down&parish=Blarisr&churchid=451
You could also try checking the land records called the Griffith's Valuation which is a land record dating from 1848-64. There may be some record of him in this or at least of his family.
Other websites that may prove useful in your search are:
The National Archives of Ireland http://www.nationalarchives.ie/genealogy1/genealogy-records/introduction/
The National Library of Ireland http://www.nli.ie/en/family-history-introduction.aspx
The National Archives UK ? genealogy search: http://www.nationalarchives.gov.uk/records/looking-for-person/
The Public Records Office of Northern Ireland http://www.proni.gov.uk/index/family_history.htm
I hope this helps,
Kind regards,
Genealogy Support
