Although he began his career as a documentarian, Aaron Siskind quickly became known for photographs that concerned themselves with exploring internal formal relationships rather than depicting recognizable objects. Active in the artistic milieu of postwar New York, Siskind made photographs in dialogue with the work of the Abstract Expressionist painters, with whom he was socially and professionally close. He sought to find a new language for photographic depiction that could transcend what was in front of the camera. “First, and emphatically,” he wrote in 1950, “I accept the flat plane of the picture surface as the primary frame of reference of the picture.” Siskind’s radically abstract photographs of walls covered with graffiti, chalk, or peeling paint and paper would be recognized as a pioneering development in 20th-century photography.