Ancestry has the family on the 1870 census in Bergen, Hackensack, NJ as:
George Mageary age 32, b. Ireland, occ: Stone Mason
Jane Mageary age 30 b. Ireland occ: Keeping house
William Mageary age 2/12 b. month of April in New Jersey
Dennis Mageary age 21 b. Ireland occ: Stone Mason
Agnes Shaw age 24, b. Ireland occ: Dressmaker
Best wishes
Jean