Cleo was born in 1926. He was the son of Erwin Davis and Florie Austin. Cleo was a fourth cousin of Loretta Lynn and Crystal Gayle.
"Kentucky, Vital Record Indexes, 1911-1999," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:QKHJ-3L8B : 11 February 2018), Cleo Davis, 1926; citing Birth, Johnson, Kentucky, United States, Kentucky Department for Libraries and Archives, Frankfort.
"United States Census, 1930," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:XMFL-DYC : accessed 6 September 2019), Cleo Davis in household of Ervin Davis, McVeigh, Pike, Kentucky, United States; citing enumeration district (ED) ED 20, sheet 11A, line 43, family 216, NARA microfilm publication T626 (Washington D.C.: National Archives and Records Administration, 2002), roll 775; FHL microfilm 2,340,510.