An overview of the “market revolution” period Clark described in detail in western Massachusetts in The Roots of Rural Capitalism. Clark outlines six areas he thinks hold the most interest: families and households, work and labor, new social structures and elites that emerge “from the interactions of households, labor, and property,” regional differences, and the tension between “extensive” growth over new territories and “intensive” development in settled areas. He anchors the narrative in a “perspective that places regional social differences at the heart of an argument about national developments. These differences were not variations or exceptions to general trends,” Clark says; “rather, their interactions were the essence of social change” throughout this period.