Michael Callahan and Mary Doyle

I am trying to find information about my great grandfather, Michael Callahan, who was born in Ireland in 1823 and died 28 February 1892 in New Haven, Connecticut, USA, and his wife, Mary Doyle, who was born in Ireland in 1834 and died in New Haven about 1900. Michael became a naturalized U.S.A. citizen 28 February 1892 in New Haven. The only other information I have is that their children were named Dennis J. Bridget, Hannah, Edward and Michael Jr., all of whom were born in New Haven between 1856 and 1876; with luck they may be family names from Ireland. I have no information on the county or parish Michael or Mary came from.