This thesis is a sociological historiography which is concerned with human networks and how these evolved and adapted to social change and dislocation in the eighteenth century. The experiences of several Campbell kinship groups who comprised a stratum of minor landed elites in the southwest Highlands are explored and analysed and particularly with regard to the extent to which their network structures assumed a predominantly horizontal spread. This structural alteration was a result ofthe absorption of exogamous ties and also a tendency for interest groups and professional configurations to establish satellite networking cliques and clusters imitative of civic participation and engagement. Although these extraneous ties brought additional stocks of social capital to the networks, these were prudently secured between social peers with strategies of social closure continuing to preserve the integrity of the networks. The nature of the relationships which the ties secured are also considered with regards to a number of conceptual theories which deal with conditions of mutual trust, cooperation, reciprocity, obligations and honour. The greatest challenge to the durability of the networks occurred with the transatlantic migrations and an increase in the volume of colonial trade. From the localised immediacy and intimacy of the Highland kinships the networks adapted to conditions of distanciation so that a networking continuum was sustained thereby linking the transatlantic clusters and cliques. As it was the networking ties not only served as channels of information but as highways which facilitated and stimulated a great deal of mobility. Although these networks may well have mitigated against many of the risks inherent in colonial trade, social closure tended to inhibit access to the wider stocks of opportunity, expertise and knowledge which lay beyond the limiting parameters of what was effectively a closed market.