Impressionism
Impressionism begins in America around 1875 and continues through the first quarter of the 20th Century. American artists modified in a clearly American manner the soft brush strokes of the French. While the list of artists that painted in an impressionist manner is lengthy, it is the works of John Singer Sargent, Childe Hassam, Mary Cassatt, Theodore Robinson, James McNeill Whistler, J. Alden Weir and J.J. Enneking that are considered the leaders of the American movement.
Regionalism
Regionalism is a distinctly American school of painting with Grant Wood, John Steuart Curry and Thomas Hart Benton as its hallmark artists. However, there are modifications to the term regionalism. The first would be the New England regionalists, the New Hope impressionists and the California School. The regionalist movement focused on the Midwest and the simplicity of the non-city way of life; typically rural American activities.
The Ashcan Movement
The Ashcan movement was a revolution against American standards in painting. The artists of this idiom painted an America overlooked by the mainstream. They chose everyday working situations and the inner working of the large city. Classical Ashcan subject are the working shop people, ladies placing laundry on the clothesline, the alcoholic or street-people, kids playing in the alleys and the perverted side of the theatre district. The timeline for the Ashcan school would be from the turn of the 20th century through the early 1930s.
American Modernism
American Modernism is perhaps defined as the void of sentimentality and personal expressiveness, and occurs after World War II. Generally, the subjects of this movement were the modern and mechanized cityscape and pockets of interest within urban views. The artists of this movement are numerous, with standouts being Stuart Davis, Louis Lozowick, Edward Hopper, and Ralston Crawford.
Contemporary
Contemporary art begins where the modernist movement ends, in the late 1940s. The artists of this period were interested in the immediate, and in its result. This movement was more about the process, the relationships of feelings and the response to such. Often referred to as abstract expressionism, is the school which attracted the likes of Willem de Kooning, Franz Kline, Jackson Pollock, Hans Hofmann and Robert Motherwell.