John Kelly & Margaret Connery

I am looking for my great-great grandparents John Kelly and Margaret Connery.  They had at least one child named Mary Kelly, my great-grandmother who married Michael Heafey. I believe John and Margaret were born in the early 1800s in Ireland.  I have found one hundred John Kellys but nothing that tells me if it is my John Kelly.  I have no clue as to which county they were from. D. Heafey-Britt