Garvagh Roman Catholic Church Book #3 list a marriage between Patrick Cassidy of Slaght, son of John Cassidy, and Nancy Mullan of Slaght, daughter of James Mullan. The marriage date is recorded as 10 June 1877 in Ballerin (probably St Mary's Church), Garvagh, Coleraine, Londonderry, Ireland. I may have a bit more info, I will check and post it later.

Julie