In November 1939, The Museum of Modern Art in New York City mounted an important Picasso exhibition entitled: Picasso: 40 Years of His Art, which contained 344 works of Pablo Picasso and his famous anti-war mural, Guernica. The exhibit led Pollock to recognize the expressive power of European modernism, which he had previously rejected in favor of American art. He began to forge a new style of semi-abstract totemic compositions, refined through obsessive reworking.
One possible influence on Pollock was the work of the Ukrainian American artist Janet Sobel (1894-1968) (born Jennie Lechovsky). Sobel's work is related to the so-called "drip paintings" of Jackson Pollock. Peggy Guggenheim included Sobel's work in her The Art of This Century Gallery in 1945. The critic Clement Greenberg, with Jackson Pollock, saw Sobel's work there in 1946, and in his essay "American-Type' Painting" Greenberg cited those works as the first instance of all-over painting he had seen, stating that "Pollock admitted that these pictures had made an impression on him".