Parish Name

I am searching for John O'Donnell wife named Birdie.  His sons Michael Bernard O'Donnell, Thomas O'Donnell and John O'Donnell immigrated to America about 1860.  Michael's obituary stated he was born in Castlereagh, Ballymacarat, County Down Ireland 11 October 1846.

I have not been able to locate the family but my uncle visited many years ago and found many headstones in the parish church with the family name.

Any help you can give will be appreciated.

Gail Entwistle