Siskind began his career in the 1930s as a social documentary photographer and member of the Workers Film and Photo League. His work took a radically new direction in the 1940s when he shifted his focus to neglected details of the man-made environment: graffiti, decaying walls, peeling paint, tattered posters, and rusted signs. Like the Abstract Expressionists, who purged their canvases of representational content, Siskind's primary concern was the compositional form of the photograph itself. As he explained in his "Credo" of 1950: "When I make a photograph I want it to be an altogether new object, complete and self-contained, whose basic condition is order-(unlike the world of events and actions whose permanent condition is change and disorder). . . . First, and emphatically, I accept the flat plane of the picture surface as the primary frame of reference of the picture."