This document provides an overview of Abstract Expressionism, a major American art movement that developed in New York City during the 1940s and 1950s. It notes that many European artists immigrated to New York during World War 2, influencing the development of innovative artworks through cross-pollination of ideas. Key Abstract Expressionist artists mentioned include Pollock, de Kooning, Rothko, and Kline. The movement is described as the first truly American school of art that was internationally influential until the rise of Pop Art in the 1960s.