In the mid-1940s, Aaron Siskind moved from the socially conscious documentary photography that had preoccupied him throughout the 1930s to increasingly symbolic and abstract photographs of discarded and found objects. “For the first time in my life subject matter had ceased to be of primary importance,” he wrote. As his subjects became increasingly abstract—often flat surfaces of rusted signs and painted walls—they shared the look and non-narrative content of paintings by Siskind’s Abstract Expressionist friends.