This essay situates the rise of US empire in the nineteenth century within a longer, transnational, and transoceanic colonial project that has been continuously catastrophic – from the arrival of Columbus to the threats of climate change and nuclear disaster – for both Indigenous societies and nonhuman ecosystems. The essay shows how such ecological and geopolitical disruptions were central to both US nation-building and the development of an American national literature, while at the same time highlighting the causal relation and essential continuity between the extractive enterprises and imperial expansionism of the early United States and the planetary crises of the twenty-first century.