As a frontier land, and later as a developing nation, the American artists were heavily influenced by the styles in art already developed to a high point in the mature societies of Europe. In the course of the 19th century, however, the country developed distinctive variations on the European models. Finally, by the middle of the 20th century in painting and sculpture, U.S. masters and schools of art were exerting a powerful worldwide influence over art.
This period of artistic leadership coincided with the country's increasing degree of international political and financial leadership, and reflected the nation's prosperity. Because of the great size of the country, stylistic variations developed within this main line of artistic growth. Regions that had been settled by different European nations reflected their early colonial heritage in artistic forms to a decreasing degree through the middle of the 19th century.
Differences persisted between the art produced in the city and that produced in the country within the various regions; rural artists, trained or untrained, were isolated from current trends and competitive pressures and produced highly individual modes of expression that were imaginative and direct, independent of prevailing formal conventions.