Modern colonialism from the eighteenth century onward encompassed most of the world’s surface. Today, the world is different. In theory at least, nation-states rather than empires and colonies are the global norm. The sorts of colonial conquests that mark earlier centuries appear to have ended. But does this mean colonialism in the past is not relevant for the present? Scholarly and popular discussions allude to the idea that past colonialism impacts the present, using a variety of terms like “legacies,” “imprints,” “vestiges,” “ruins,” or “afterlives.” Yet existing scholarship has yet to fully clarify and catalog the specific processes and mechanisms that connect colonial history with its putative legacies. This essay, based upon the 2022 Presidential Address to the Social Science History Association, identifies and discusses four such processes and mechanisms or “modes of reverberation”: (1) continued colonialism through simple reproduction, (2) the persistence of power through formal and informal institutionalization, (3) path dependent historical trajectories (or “colonial institutionalism”), and (4) colonialism’s archive of meaning.