Birth Certificate

Extract from the 1930 census of Manhattan, New York. The pertinent information is on line 45.
The census indicates that Edward Josepeh Duffy, age 21, was a lodger at the residence of Mary Keny (née McDonagh), as was his sister, Cathleen Duffy (see line 46). Later on, in 1934, Edward was to marry Mary "Mae" Ellen Torpey, the neice of Mary Keny. Mae's brother, Patrick "Packy" O. Torpey, was also a lodger with Mary Keny (see line 40).

Certificate of Marriage

Extract from 1940 census of Manhattan, New York
The census shows (starting at line 67) that Edward J. Duffy, age 32, was the married head of a household whose occupation was a manager of a retail establishment. The household included (1) his wife Mary, age 31, (2) his son Edward Joseph, age 5, (3) his son James P., age 3 1⁄2, and (4) his daughter Mary Ann, age 1.
The extract also shows (starting at line 52) that Edward's sister Katherine was then living with her husband, James J. Coburn, and their children, Margarite M., age 4, and John Hugh, age 1.

Extract from 1950 census of Manhattan, New York
The census shows (starting at line 12) that Edward J. Duffy, age 42, was the married head of a household whose occupation was a sales clerk at a grocery. The household included (1) his wife Mary, age 41, (2) his son Edward J., age 15, (3) his son James P., age 13, (4) his son Kevin J., age 8, (5) his daughter Mary A., age 11, (6) his son Michael D., age 5, and (7) his son Brian A., age 1.