Implicit in recent debates among historians of human rights is the question of whether and how early rights promises, particularly eighteenth-century rights declarations, enabled later rights claims. Can promises, initially unrealized, create the conditions for their own fulfillment? Reading Hannah Arendt with Arthur Danto, this article offers an account of human rights politics as a practice of repeated promise-making – one characterized not by reliance on the past as a stable foundation, but by uncertainty about, and contestation of, history. Using archival sources, it also reconstructs Arendt's and Danto's involvement in human rights politics, including Danto's early role in Amnesty International USA.