Family tree▼
"United States Census, 1920", database with images, FamilySearch (https://www.familysearch.org/ark:/61903/1:1:MDTW-X3Z : 3 February 2021), Mary Herdman in entry for Harry L Ferguson, 1920.
"Ohio, County Marriages, 1789-2016", database with images, FamilySearch (https://www.familysearch.org/ark:/61903/1:1:K3GK-77N : 29 September 2021), Robert Spencer Schwingel and Mary Elizabeth Herdman, 1938.