Land use and land tenure in the Uists has evolved over the past two centuries fashioned by the possibilities offered by the varying qualities of soils and terrain and by economic circumstances, estate and government policies. At the end of the 18th century, estate surveys and plans provide a detailed account of the patterns of tenure and land use. The crofting system, created between 1814 and 1818, with the aim of improving agricultural standards and as a means of maintaining a labour force to manufacture kelp, led to an expansion of the cultivated area. In the middle of the 19th century, large farms displaced much of the population and resulted in congestion in the remaining crofting townships and very intensive use of the available land. Government intervention led to the settlement of crofters on the majority of the farms after 1890. Since the ‘agricultural revolution’ of the 1950s, if the number of active crofters and croft units and the area of cropped land has declined, the size of the effective croft units and their cattle stocks has increased, particularly in the more recently formed townships. Cereal cropping is now virtually confined to the machairs and most of the crofts are under permanent grass.