Looking for Hanlon (O'Hanlon) of Armagh

Hello

Looking for information about my 2nd great grandfather, Thomas Hanlon (possibly O'Hanlon). It is believed his parents were Hugh Hanlon and Margaret Dickenson. He was born early 1830's. The story is that he came to America with his brothers, Hugh and John Hanlon mid 1850's and they were from Armagh. Thomas married Mary Ryan about 1862 in New York City, where he was a stonecutter. He died in 1904 in NYC and I obtained a copy of his death certificate, but unfortunately, it did not state first names of parents.

Any information or guidance is very appreciated.

Pat M.