In 1920, John and his sister Mary are listed with the same age, 12, implying that they were twins. The census was enumerated on 5 Jan 1920, and the age listed was as of their last birthday. So, an estimated year of birth would probably be 1907. It is interesting that his first <a href="#name"></a>two children are named Mary and John.
In 1925, when Mary married John Sullivan, her birth year was given as 1907, meaning she was 18 when she got married, and her birth date would be sometime before 22 Jun 1907.
John's petition for naturalization states his birthday as 21 May 1908. Census errors happen all the time, and some locales require the bride to be 18, so little fibs are told all the time. And they may not be twins. Curiously, data from the 1920 census suggests that all family members were naturalized in 1910. Perhaps, that was meant to be temporary, to be confirmed as a adult, or perhaps when John went back to Canada, his status as a naturalized citizen, conferred when he was two, was cancelled.
We also learn that he entered the US Army on 23 Oct 1945.
John's petition for naturalization stated his wife's name was Mary M., and that they had five children all born and living in Boston. by <a id="name">name</a>:
Mary, b. 30 Mar 1934
John, b. 27 Dec 1936
Lucy, b. 1 Sep 1939
Barbara, b. 17 Jul 1942
Dorothy, b. 20 Jan 1945
Did he enlist with the military in Canada about 1939?
How are all his children born in Boston, live in Boston, yet he emigrated from Windsor, Ontario, Canada on the MCRR, under his real name, on 22 Apr 1945, after his last child was born in Boston, and then enlist in the US Army?
Based on the 1920 Census, John and Mary may have been twins. See the Research Notes on her profile for an explanation of the birth year of 1907, rather than 1908.
↑ 1.01.1 "United States Census, 1920," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MFMZ-78Y : accessed 6 October 2020), John L Campbell in household of John W Campbell, Boston Ward 3, Suffolk, Massachusetts, United States; citing ED 65, sheet 4B, line 84, family 85, NARA microfilm publication T625 (Washington D.C.: National Archives and Records Administration, 1992), roll 729; FHL microfilm 1,820,729.
↑ "Massachusetts Marriages, 1841-1915," database with images, FamilySearch (https://www.familysearch.org/ark:/61903/1:1:Q28K-C5G1 : 3 June 2020), John W Campbell in entry for John J D Sullivan and Mary E Campbell, 28 Jun 1925; citing Boston, Suffolk, Massachusetts, United States, State Archives, Boston; FHL microfilm 831,842.