Set in Manhattan in the early 1940s, the film focuses on the title character, an aging, bearded, disheveled bohemian and Harvard University graduate who wanders through the streets of Greenwich Village carrying a tattered portfolio and demanding donations to "The Joe Gould Fund." At times he is calmly sweet and perceptive, at others he's a pathological liar and an obnoxious drunk, and he frequently experiences sudden outbursts of rage. Earning occasional financial support from poet e.e. cummings, portrait painter Alice Neel, Village Vanguard founder Max Gordon, and art gallery owner Vivian Marquie, among others, Gould is able to secure a nightly room in flophouses until an anonymous benefactor arranges accommodations in a residential hotel for him. Gould allegedly is collecting the observations of average citizens to incorporate into his oral history of the world, fragments of which he has given to various people for safekeeping. Joseph Mitchell, a writer for The New Yorker, meets him in a coffee shop and initially is fascinated by the colorful character. However, with the passage of time, as Gould becomes irritatingly intrusive and demanding, disrupting the ordinary life Mitchell shares with his photographer wife and their two daughters, the journalist begins to question if the elderly man's 9 million-word opus actually exists or is merely a figment of his imagination.