Siskind, Aaron, 1903–91, American photographer, b. New York City. A member of the Photo League in the 1930s, he began as a documentary photographer, creating such series as Dead End: The Bowery and Harlem Document (1932–40). Aiming to make photographs aesthetic objects in their own right, in the early 1940s Siskind began to create the abstract images for which he is now principally known. Shooting at close range, he photographed graffiti, peeling plaster, sections of signs and billboards, road surfaces, and various organic and found objects. Many of his powerful 1950s images clearly relate to the paintings of his abstract-expressionist friends such as Kline, Motherwell, and de Kooning, and he radicalized photography much as those painters revolutionized their medium. Siskind's photographs, even his late series of midair divers, remained essentially abstract for the rest of his career. A very influential teacher, he (and his friend and colleague Harry Callahan) taught at Chicago's Institute of Design (1951–71) and the Rhode Island School of Design (1971–76). His work has been published in a number of books, notably Aaron Siskind, Photographer (1965), Places, 1966–1975 (1976), Aaron Siskind 55 Series (2003), and Aaron Siskind 100 (2003).