Why are some constitutions amended more frequently than others? Studies of amendment rates have been plentiful but have not generated much theoretical or empirical consensus because the extant literature rests rest on a strong and unwarranted assumption that social capacity to navigate amendment rules is constant across space and time. By contrast, the authors of this Element argue that this social capacity varies by civic connectedness. Drawing upon previous studies that find social capital mitigates transaction costs, this Element outlines the myriad ways in which social capital helps elites, social movements, and ordinary citizens solve the collective action problems associated with constitutional reform. The authors find evidence for their theory using a variety of measures, methods, and units of analysis.