In 1982 sociologist Howard Becker observed in Art Worlds that "all artistic work, like all human activity, involves the joint activity of a number, often a large number, of people." His observation was in tune with the times: in the quarter century since, historians of art, historians, and sociologists alike have done much to elucidate "the complexity of the cooperative networks through which art happens."1 Nonetheless, there are still many words that could be said about "worlds." Indeed, once we begin to conceive of the American art world (or, more precisely, the American art world at any given moment in history) as an entity in its own right, we may analyze not only the subsets within that set but also the relationships between one art world and another. We may, for example, analyze large-scale transitions between different historical art worlds in the United States, or explore the almost limitless ways in which they overlapped, intersected with, or paralleled those of other places.