Masterworks of Modern Photography 1900-1940. The Thomas Walther Collection at The Museum of Modern Art, New York.The extraordinary fecundity of the photographic medium between the first and second world wars can be persuasively attributed to the dynamic circulation of people, of ideas, of images, and of objects that was a hallmark of that era in Europe and the United States. Voluntary and involuntary migration, a profusion of publications distributed and read on both sides of the Atlantic, and landmark exhibitions that brought artistic achievements into dialogue