Hello, I don't know if you've already checked census records, but this seems to be the family in the 1930 census for MA: | Cornelius O'Neill | Head | M | 59 | Irish Free State | | Mary O'Neill | Wife | F | 59 | Irish Free State | | John J O'Neill | Son | M | 30 | Massachusetts | | Edward J O'Neill | Son | M | 21 | Massachusetts | | Lawrence Dunne | Lodger | M | 60 | Irish Free State | | John T Dunne | Lodger | M | 17 | New York | | Joseph J Dunne | Lodger | M | 17 | New York | And, also at   www.familysearch.org     I don't see another John, with a father Cornelius - in MA. In 1920 this is the family.    Have you tried locating the other children? | Cornelius O'Neill | Head | M | 49 | Ireland | | Mary C O'Neill | Wife | F | 48 | Ireland | | Mary A O'Neill | Daughter | F | 24 | Massachusetts | | Nora G O'Neill | Daughter | F | 21 | Massachusetts | | John J O'Neill | Son | M | 20 | Massachusetts | | Jeremiah L O'Neill | Son | M | 15 | Massachusetts | | Christopher O'Neill | Son | M | 13 | Massachusetts | | Edward O'Neill | Son | M | 10 | Massachusetts | And, did any of the sons fight in WW I  or  WW II  ? There seems to have been 3 or 4  John O'NEILL's born in Greater Boston ~1900, and all had different fathers. There is a John J. O'NEILL living in Washington, DC, in 1940.    If you look closely at the actual page,  he is among the patients at Saint Elizabeth's Hospital there.     It's possible he was a soldier at that time. Is this his  WW I  Draft Registration card?    It says he was a student at Boston College.    Having his exact birthdate would help to find the correct birth record. | Name | John Joseph O'Neill | | Event Type | Draft Registration | | Event Date | 1917-1918 | | Event Place | Somerville City no 3, Massachusetts, United States | | Gender | Male | | Nationality | United States | | Birth Date | 09 Oct 1899 | | Birthplace | , , United States That's all for now. Betty          (near Lowell, MA) List Administrator P.S. In 1940, there is a family in the bordering town of Arlington, MA: | John J O'Neil | Head | M | 41 | Massachusetts | | Mary L O'Neil | Wife | F | 44 | Massachusetts | | John J O'Neil | Son | M | 15 | Massachusetts | | Paul F O'Neil | Son | M | 14 | Massachusetts | | Ann E O'Neil | Daughter | F | 12 | Massachusetts | | Joseph O'Neil | Son | M | 10 | Massachusetts | | Robert A O'Neil | Son | M | 4 | Massachusetts | |