This document summarizes the Abstract Expressionist movement in American art from the 1940s-1950s. It profiles key Abstract Expressionist artists like Arshile Gorky, Willem de Kooning, Jackson Pollock, Mark Rothko, and Franz Kline and their signature techniques like action painting and large-scale gestural brushwork. It also discusses how Abstract Expressionism influenced later movements like Neo-Expressionism, Pop Art, and Post-Painterly Abstraction.