William Black was the son of Thomas Nielson Black and his first wife Margaret McKinnell. Both of his parents were born in Scotland. Thomas emigrated to America in 1847 and was counted on the 1850 census with his parents and siblings in Elizabeth, Allegheny, Pennsylvania. As is the Scottish custom William was named for his paternal grandfather.
Thomas and Margaret had four children, William born 1855 in Pennsylvania; Elizabeth born born 1857 in Pennsylvania; Isabella born 1859 in West Virginia and Helen born 1864 in Zanesville, Ohio. Although the family cannot be located in the 1860 census the births help to pinpoint their locations.

William's mother died in March of 1865 in Zanesville. His father then married Louisa Romine November 25th of that same year. William's grandmother Isabella, a widow, was living with the family as she died in Zanesville in 1869.

In 1870 the family was still residing in Zanesville. Father Thomas was employed as a superintendent of a coal mine. Daughters Louisa and Mary have been added to the household. William now 15 works in a coal mine.

William and Margaret Wallace were married August 4, 1879 by L.C. Haddox minister of the Methodist Episcopal Church in Haydenville, Hocking County, Ohio. The marriage application was made by her father who needed to give consent as she was under 18 years of age.

In 1880 William and Margaret lived in York, Athens, Ohio. On the same census sheet is William's father Thomas and family. Thomas's occupation was Mine Superintendent and William's was Assistant Superintendent. It is likely they worked at the same mine.

William met an unfortunate death in 1890 when he mistook a bottle of carbolic acid for cough medicine. By this time he and Margaret had three children, Thomas Nielson Black; Sarah Louise "Lula"and Lizzie Belle "Belle".

Margaret raised their three children in Nelsonville. After they were all married she moved to Columbus about 1916 where the children were then living. Margaret did not remarry until 1927.