Drawing on a variety of data sources--national surveys and censuses, probate and tax records, wage series and rich lists--I identify five period or regimes in US history with distinct wealth and income distributions. I argue that this periodization of inequality in the United States is a product of Arrighi's systemic cycles of accumulation. Each cycle of accumulation is associated with a spatial configuration, a global pattern of interdependent technologies, infrastructure, institutions, networks and social relations, and ideologies, that structures the distribution and flow of wealth. Interdependence in the components of the spatial configuration means that there are periods of relative stability delineated by moments of cascading change when space is reconfigured; new patterns of wealth and income concentration emerge as a result. The principal contribution of this approach is to further our understanding of the impact of global processes on within-country wealth and income concentration; we cannot isolate domestic market institutions and technological change from global political and economic competition.