William was the son of Major William Conley and Mary Freeburn. His siblings were Mary Ellen, John Allen, Edward Bunker, Ellen, and Mattie.
William married Bertie Ison Martin of Preston County. They had the following children:
Lillian May, b. 3 Aug 1893
William G. b. 8 July 1895
Marian, b. 26 Dec 1896
Donald M., b. 15 Dec 1899
james S., b. 12 June 1905
From "This Week in West Virginia History", West Virginia Public Radio:
The Republican started his career as a schoolteacher and became superintendent of Preston County schools at age 25. After earning his law degree, he opened a legal practice in Tucker County and founded the Parsons Advocate newspaper. He also served as mayor of Parsons and Kingwood before being appointed West Virginia attorney general in 1908.
"United States Census, 1900," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M9Z6-CZ9 : accessed 26 March 2018), William G Conley, Black Fork district (Hendricks & Parsons towns), Tucker, West Virginia, United States; citing enumeration district (ED) 134, sheet 14B, family 291, NARA microfilm publication T623 (Washington, D.C.: National Archives and Records Administration, 1972.); FHL microfilm 1,241,773.
"United States Census, 1910," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MPN6-G83 : accessed 26 March 2018), William G Conley, Charleston Ward 7, Kanawha, West Virginia, United States; citing enumeration district (ED) ED 71, sheet 4A, family 60, NARA microfilm publication T624 (Washington D.C.: National Archives and Records Administration, 1982), roll 1684; FHL microfilm 1,375,697.
Obituary of William Gustavus Conley, Charleston Daily Mail, October 22, 1940; transcript available at www.wvculture.org/HISTORY.