 In 1871 he resigned from the council, and the following year was returned to the South Australian House of Assembly for Sturt.He joined the seventh Henry Ayers ministry as Treasurer of South Australia in March 1872, holding the position until Ayers resigned in July 1873.John Barrow was also the first Mayor of the newly created municipality of the Town of Unley, and was an active member of the South Australian Free Rifle Corps.