In counterpoint to long-running perceptions of the United States and the Americas as continental spaces, this introduction describes a centuries-long and spatially splayed space termed the archipelagic Americas, composed of islands, island chains, and island-continent relations. The project of archipelagic American studies emerges as a study of the archipelagic Americas’ interlinked cultures, a project dedicated to tracing the interrelations and overlaps of a broadly construed America and the larger archipelago of islands that spans the planet. The introduction further traces key features of a postcontinental and archipelagic American imaginary, outlining reading practices that hold in tension the planetary and the microregional. Ultimately, the collection of essays functions as an archipelago of islands, an assemblage aiming to crystallize emergent trends in Americanist scholarship, namely, a turn toward approaching islands, island-sea assemblages, and coastline formations that goes beyond colonialist tropes and requires a new world of archipelagic understanding.