In the 1851 census Little Bell Alley, St. Stephen Coleman Street, London, Middlesex
Head John Blackburn, age 32, carpenter, born Ripon, Yorkshire
Wife Sarah Blackburn, age 32, born Leeds, Yorkshire
Daughter Mary Blackburn, age 8, born London
Daughter Emma Blackburn, age 6, born London
Son Alfred Blackburn, age 5, born London
Son John Blackburn, age 2, born London
Father James Blackburn, married, age 57, carpenter, born Ripon
Sister [presumably Sarah’s sister], Emma Olbrid, unmarried, age 22, dressmaker, born Leeds.