William Black Wellner was born 19 June 1809 in Halifax, Nova Scotia to William and Elizabeth (Ives) Wellner. William was living in Prince Edward Island by the late 1830s and married Jane Ann Wright 1 May 1842. William and Jane lived in Crapaud where William was a Justice of the Peace, performing marriages as early as 1839. William and Jane had six children, including William Wright, John Ives, Elizabeth Jane, Frances Black, Charles Wright and Warren Lord, however only William, Frances and Warren survived their infancy.

Around 1847 the Wellner family moved to Charlottetown where William was very active in civic affairs. At the first council meeting of the newly incorporated city of Charlottetown in 1855, William was appointed city clerk. William was also employed as a merchant and bookkeeper in Charlottetown. William died 3 March 1892 in Covehead, Prince Edward Island.