Abstract Expressionism emerged in New York City in the 1940s-1950s as an American art movement focused on spontaneous, emotional, and abstract qualities rather than objective representation. Key figures included Jackson Pollock, whose action painting involved dripping and splattering paint, as well as Mark Rothko, whose color field paintings used large areas of color without edges. The movement emphasized personal expression and the act of painting over recognizable imagery, influencing later art styles through its rejection of realism.