Why was Jackson Pollock’s painting Mural an important breakthrough?

Jackson Pollock’s Mural (c. 1943–44) was a significant breakthrough because it marked his transition into a totally personal artistic style.1

In this wall-sized work, Pollock successfully fused the compositional methods and energetic linear invention he learned from Thomas Hart Benton with the Surrealist practice of free association and unconscious imagery. This synthesis represented a pivotal step in his evolution, as he began the long-term struggle to develop a process that would allow him to translate his entire personality into his painting.1

By moving away from his earlier influences and integrating these disparate elements, Mural set the stage for the development of the techniques he would employ throughout the 1940s, eventually leading to his signature Abstract Expressionist "poured" paintings.21