Peter Allen Campbell was born in Boston, Massachusetts to John Warfield Campbell and Jennie L. McLellan on 12 January 1914. The record confirms that John and Jennie were both born on Prince Edward Island. John was a "Teamster". 
Peter appeared in the 1920 U.S. Census at age 6 with these parents and siblings. 
"Massachusetts, Town Clerk, Vital and Town Records, 1626-2001," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:Q2Q2-SCH7 : 6 April 2020), John Warfield Campbell in entry for Peter Allen Campbell, 12 Jan 1914; citing Birth, , Suffolk, Massachusetts, United States, Massachusetts Secretary of the Commonwealth, Boston; FHL microfilm 007604894.
"United States Census, 1920," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MFMZ-7DM : accessed 3 October 2020), Peter A Campbell in household of John W Campbell, Boston Ward 3, Suffolk, Massachusetts, United States; citing ED 65, sheet 4B, line 87, family 85, NARA microfilm publication T625 (Washington D.C.: National Archives and Records Administration, 1992), roll 729; FHL microfilm 1,820,729.