Abstract: This article considers a curious document – Baker’s Australian County Atlas – which contains carefully illustrated maps of each of the 19 counties in the colony of New South Wales in the mid-1840s. The analysis seeks to bridge the gap between high-level geographical studies of the British invasion of New South Wales and historical analysis of settler colonial property formation. We argue that the Atlas reveals the mechanics of territorial accumulation and Aboriginal dispossession in nineteenth-century New South Wales in their historical and material specificity, locating instances of ‘improvement’ – clearing, fencing and the construction of temporary and permanent buildings – at the centre of settler colonial land administration and sovereignty. The article demonstrates that the legal obligation to improve ultimately regulated colonial urbanization, enacting a process in which buildings and other structures functioned less as ends in themselves than as discrete operations within a more pervasive and abiding process of dispossession.