The line had its origins in Railway Commissioner Goodchap's 1882 recommendation that an additional line was needed between Newtown and Liverpool to relieve traffic on the Southern Line and to encourage agriculture and suburban settlement. Lobbying by local interests and land speculators achieved Parliamentary approval by 1890 and construction commenced in 1892. The most important stations on the line, Belmore, Canterbury and Marrickville, were built with impressive near-identical brick buildings, the other intermediate stations (Campsie, Dulwich Hill and Hurlstone Park) receiving more modest timber buildings (later replaced), possibly reflecting economies of the depression of the 1890s.
