I'm researching my children's paternal line...it is O'Connor. Earliest ancestor was known to be born in Ireland, but do not know where. First one in America:
John O'Connor, b: abt 1815 in Ireland. Married: Mary O'Connell, also born in Ireland.
Their son, John O'Connor was born in Shamokin, Northumberland, Pennsylvania in 1852. This John married Susan Coulston who was born in 1856 in Philadelphia.
This family migrated to Chicago, Cook, Illinois.