Just off the coast of the Bronx in Long Island Sound sits Hart Island, where more than one million bodies are buried in unmarked graves.

Beginning as a Civil War prison and training site and later a psychiatric hospital, the location became the repository for New York City's unclaimed dead. The island's mass graves are a microcosm of New York history, from the 1822 burial crisis to casualties of the Triangle Shirtwaist fire and victims of the AIDS epidemic. Important artists who died in poverty have been discovered, including Disney star Bobby Driscoll and playwright Leo Birinski. Author Michael T. Keene reveals the history of New York's potter's field and the stories of some of its lost souls.