As an instrument for governance, summitry is a novel structure for the management of contemporary hemispheric regionalism in the Americas. Such regionalism is a clear case of the “structuralist paradox” of international cooperation. This article attempts to explain the particular asymmetric regionalism in the Americas by using the concept of cooperative hegemony. The underlying hypothesis is that the U.S. government, since 1994, has pursued a strategy of cooperative behavior, at least in regard to power sharing, in two specific phases of hemispheric regionalism: agenda setting and institutionalization. This study tests the hypothesis through a content analysis of the main documents produced at the Miami, Santiago, and Québec summits, then relates these findings to the progress of institutionalization from 1994 to 2003.