Both the expansion and the formalization of New York society and the season after the Civil War were directly related to the city’s rapid demographic and economic growth. The convergence upon New York of newly enriched fami­ lies and individuals, in addition to the emergence of New York’s own nouveaux riches, put considerable stress upon existing social structures. Prevailing methods of social placing used by New York’s elite proved inadequate with the increase in geographic and social mobility, and so more elaborate methods were introduced in order to preserve its power and status. At the same time, some degree of flexibility was necessary to prevent the elite’s complete and utter dis­ placement by those with superior financial resources, and so in the 1870s and 1880s the social mechanisms that were put in place allowed for a controlled merger of old and new wealth.