David McMillan Mason was born on 9 March 1886 at New Cumnock.

He married Janet Wilson Love on 30 June 1922 at New Cumnock.

David and Janet had a son, William Mason born 1924. William married Agnes Paterson Burgoyne on 7 June 1946 at New Cumnock.

William and Agnes had a son, David McMillan Mason born 1947.