Aquestion for anyone who cares about modernist art: why is John Quinn not better known? He should be celebrated as one of the most remarkable people in the history of advanced taste in the United States, a dedicated supporter of vanguard literature and art who profoundly influenced the course of modernism in America. Yet despite his having assembled a collection of over 2,000 significant modern paintings, sculptures, and works on paper in a little over a decade, and despite his having lent a prodigious number of works to the celebrated 1913 Armory Show, say the name “John Quinn” and the response is usually a puzzled “Who?” Other pioneering American enthusiasts for European vanguard art are familiar not only to art lovers, but also often to the general public. We know about Albert Barnes, Quinn’s near coeval and frequent rival for the work of particular artists. We know about the Cone sisters, Albert Gallatin, Chester Dale, Gertrude Vanderbilt Whitney, Solomon R. Guggenheim and his niece Peggy, Duncan Phillips, and the entire Stein family. It can be argued that the names of these collectors resonate because the art they chose is either showcased in eponymous museums that they themselves founded or displayed in coherent groupings in important institutions. The Steins’ family name is permanently associated with advanced art of the early twentieth century, even though their holdings are now widely disseminated, thanks to Gertrude’s assiduous self-promotion. (Happily, a recent exhibition made clear that