William was the son of W. J. Frantz and Sarah Taylor. He was an axe maker. He lived in Warren, Pennsylvania at the time of his marriage to Nellie Lucie.
"New York, County Marriages, 1847-1848; 1908-1936," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:FF51-PDZ : 25 September 2017), William L Frantz and Nellie E Lucie, 29 Nov 1913, Chautauqua, New York, United States; citing ref. ID , county clerk’s office,; FHL microfilm 1,004,674.