In recent years rural sociologists concerned with the sociology of agriculture have taken up analysis of agricultural class relations. The institutional and geographical patterns of American agriculture arise under circumstances of general commodity production and are not constrained by the geographies of earlier historical periods. Urbanisation as a process constructs both the urban and the rural, the city and the countryside, as the differentiated and segregated geography consequent to this space-forming process. Capital in agriculture encounters problems which capital in manufacturing is not subject to. Agricultural regions are thus constituted by the complex relationship between farmers and the other institutions of the agricultural sector, and between agriculture and capital-in-general. The long term implications for the structure and form of commodity production may be profound. The subsumption of farming to capital in general occurs through complex processes and involves restructuring of relations both internal and external to the farm and to the farming sector sensu strictu.