john dadford was the third son of the canal engineer thomas dadford and his wife frances brown, the daughter of a wolverhampton toymaker called samuel brown. they lived in the wolverhampton area, and it is probable that john was born in that area. his older brothers were thomas and james, both of whom worked as canal engineers. he had a younger brother called william and a sister called mary. he is known to have been a pupil at sedgley park roman catholic school between may 1778 and june 1781.