If it's any help, the 1880 census (New York, NY) has a Mary, aged 27, and a John, aged 28, as born Ireland, with their mothers and fathers also born Ireland. The eldest child, William, aged 7, was born New York.
Gadget
Added - There is also a family that matches in Philadelphia (Richard's POB) but John is down as 40 (i.e. born 1840 ish).