My paternal grandfather, Michael Clerkin, was from Monaghan. He came to New York City area when he was a teenager, worked for a few years and married Margaret Herrick. He had 3 children: Thomas (1932), Alice, and Joseph. I will try to get more detailed info.
I am one of the 12 children of Thomas James Clerkin. There are currently 24 grandchildren in this branch.
You can e-mail me directly for more information.
Clare