American Impressionist painter Frederick Childe Hassam (1859-1935) born in Boston, Massachusetts: Frederick Childe Hassam (1859-1935) born in Boston, Massachusetts, was a prominent and prolific American Impressionist painter, noted for his urban and coastal scenes. Along with Mary Cassatt and John Henry Twachtman, Childe Hassam was instrumental in promulgating Impressionism to American collectors, dealers, and the museums. Hassam produced over 3,000 paintings, watercolors, etchings, and lithographs in his career, and was a founding member of The Ten, an influential group of American artists of the early 20th century. Childe Hassams' most famous works are the Flag paintings, completed during World War I.