which of these paintings is considered an abstract expressionist painting?
Abstract Expressionism emerged in a climate of Cold War politics and social and cultural conservatism. World War II had positioned the United States as a global power, and in the years following the conflict, many Americans enjoyed the benefits of unprecedented economic growth.В But by the mid-1950s the spirit of optimism had morphed into a potent mix of power and paranoia. Fueled by the fear of Communist infiltration, Senator Joseph McCarthy of Wisconsin unleashed a series of вЂњwitch-huntsвЂќ against alleged Communist sympathizers. Any hint of subversion could make an individual suspect. One scholar later reflected: вЂњIt is ironic but not contradictory that in a societyвЂ¦in which political repression weighed as heavily as it did in the United States, abstract expressionism was for many the expression of freedom: the freedom to creative controversial works of art, the freedom symbolized by action painting, by the unbridled expressionism of artists completely without fetters.вЂќ 1
Discover the innovative tecniques of Abstract Expressionist painters
Experimentation with colors and evoking emotions was a primary interest of abstract artists. German Expressionism is characterized by its saturated palette and the colors correspondence to human emotions. German Expressionism painter, Wassily Kandinsky is often considered the first true abstract artist. He became known for his color theory and attaching emotions to his vividly colored paintings. Like many other abstract artists, Kandinsky believed that music also embodied abstract art in the purest sense, with its ability to be expressive without representing the real world. Kandinsky would go on to refer to his works as “compositions”.
Early intimations of a new art had been made by James McNeill Whistler who, in his painting Nocturne in Black and Gold: The falling Rocket, (1872), placed greater emphasis on visual sensation than the depiction of objects.
Abstract art uses visual language of shape, form, color and line to create a composition which may exist with a degree of independence from visual references in the world.  Western art had been, from the Renaissance up to the middle of the 19th century, underpinned by the logic of perspective and an attempt to reproduce an illusion of visible reality. By the end of the 19th century many artists felt a need to create a new kind of art which would encompass the fundamental changes taking place in technology, science and philosophy. The sources from which individual artists drew their theoretical arguments were diverse, and reflected the social and intellectual preoccupations in all areas of Western culture at that time. 
Abstract Expressionism, broad movement in American painting that began in the late 1940s and became a dominant trend in Western painting during the 1950s. The most prominent American Abstract Expressionist painters were Jackson Pollock, Willem de Kooning, Franz Kline, and Mark Rothko. Others included Clyfford Still, Philip Guston, Helen Frankenthaler, Barnett Newman, Adolph Gottlieb, Robert Motherwell, Lee Krasner, Bradley Walker Tomlin, William Baziotes, Ad Reinhardt, Richard Pousette-Dart, Elaine de Kooning, and Jack Tworkov. Most of these artists worked, lived, or exhibited in New York City.
Abstract Expressionism had a great impact on both the American and European art scenes during the 1950s. Indeed, the movement marked the shift of the creative centre of modern painting from Paris to New York City in the postwar decades. In the course of the 1950s, the movement’s younger followers increasingly followed the lead of the colour-field painters and, by 1960, its participants had generally drifted away from the highly charged expressiveness of the Action painters.
The abstract expressionists were mostly based in New York City, and also became known as the New York school. The name evokes their aim to make art that while abstract was also expressive or emotional in its effect. They were inspired by the surrealist idea that art should come from the unconscious mind, and by the automatism of artist Joan Miró.
Within abstract expressionism were two broad groupings: the so-called action painters, who attacked their canvases with expressive brush strokes; and the colour field painters who filled their canvases with large areas of a single colour.