This paper examines the extent to which sectoral trends and fluctuations in the Australian economy can be understood using international trade theory and knowledge of key policy developments. It suggests they are consistent with theory, but it also reveals several features that make Australia's economy unusual. The most striking are the facts that (i) the agricultural sector's share of GDP remained fairly constant rather than falling during 1860–1960 and even during the latest mining boom; and (ii) the farm sector continued to enjoy a strong comparative advantage despite periodic spurts of growth in mining exports.