Originally a Coal Miner and later a Pithead Worker, William married Annie McMillan.

They had ten children:

David McMillan Mason born 9 March 1886, New Cumnock. Married Janet Wilson Love.

William Mason born about 1890. Married Lilian Amy Bickell.

John Mason born about 1892

Gilbert Mason born about 1894. Married Mary Thompson McMurdo.

Robert Mason born about 1895

Mary McClymont Mason born about 1899. Married John Stewart (9 February 1927, New Cumnock)

Samuel Mason born about 1900

Elizabeth Boyd Mason born about 19 December 1901. Died 1997

Archibald Thom Mason born 21 May 1905, Connelpark. Married Jean Jessie Pottinger. Arcjbald was a Draper.

Annie McMillan Mason born 12 April 1909. Married Daniel Pollock Appleyard.