Abstract Expressionism was the first specifically American art movement to achieve international influence, shifting the center of the art world from Paris to New York City after World War II. Led by artists like Jackson Pollock, Mark Rothko, and Willem de Kooning, the movement emphasized the act of painting itself as a form of expression. Pollock became famous for 'action painting,' where he dripped and splattered paint onto canvases laid on the floor, capturing the physical movement of his body. Rothko, on the other hand, represented the 'Color Field' branch, using large planes of color to evoke deep emotional and spiritual responses. These artists sought to express 'universal truths' and the internal human condition through non-representational forms, forever changing the definition of what art could be.