American art in the Twenties and Thirties was not largely influenced by the Modernist artists who worked in Europe. There are no hints of Picasso or Matisse or Chagall or Mondrian or Braque, no departures in the meaning or purposes of representation, whether that means Picasso’s distortions of what is visible and invisible about a figure, superimposing parts of bodies so that a number of moments can be appreciated as simultaneous, nor of Chagall’s fanciful use of legend with no great respect for what would have been considered what is appropriate to a single composition, nor Matisse’s use of color and alteration of perspective so as to create very psychologically intense pictures of spaces and viewpoints, nor the geometry of Mondrian and Braque replacing subject matter entirely. Rather, what the American artists of the Twenties and Thirties try to do, I think, is to counter or adapt to the other visual art that had intruded into the cultural spotlight, and that was photography. This thesis is an application of what I call “The Laocoon Principle”, in honor of Gottfried Lessing, the eighteenth century aesthetician who focussed on the way the nature of a medium impacts on what an artist presents. The American artists did not face up to Modernism because of their preoccupation with distinguishing themselves from or imitating or adapting to photography, an art form taking up ever more room, especially ever since photographs rather than engravings had become a main feature of Twenties newspapers, what with their visual coverage of the slum poor, perp walks and urban construction.