(Research):https://www.findagrave.com/memorial/35821378
"United States Census, 1920," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M6QP-M1J : accessed 17 April 2020), Leon G Poole in household of Edward W Poole, Braddock, Frederick, Maryland, United States; citing ED 92, sheet 3B, line 54, family 53, NARA microfilm publication T625 (Washington D.C.: National Archives and Records Administration, 1992), roll 673; FHL microfilm 1,820,673.
"United States Census, 1930," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:X34V-K8K : accessed 17 April 2020), Leon G Poole in household of Edward Poole, Brunswick, Frederick, Maryland, United States; citing enumeration district (ED) ED 50, sheet 4B, line 56, family 90, NARA microfilm publication T626 (Washington D.C.: National Archives and Records Administration, 2002), roll 874; FHL microfilm 2,340,609.
"United States Census, 1940," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:K7FC-WLZ : 6 February 2020), Leon G Poole in household of Edward L Poole, Braddock Heights, Election District 24, Frederick, Maryland, United States; citing enumeration district (ED) 11-57, sheet 10B, line 62, family 206, Sixteenth Census of the United States, 1940, NARA digital publication T627. Records of the Bureau of the Census, 1790 - 2007, RG 29. Washington, D.C.: National Archives and Records Administration, 2012, roll 1549.