Hudson River school paintings reflect three themes of America in the nineteenth century: discovery, exploration, and settlement.

The paintings also depict the American landscape as a pastoral setting, where human beings and nature coexist peacefully.

Hudson River School landscapes are characterized by their realistic, detailed, and sometimes idealized portrayal of nature, often juxtaposing peaceful agriculture and the remaining wilderness, which was fast disappearing from the Hudson Valley just as it is coming to be appreciated for its qualities of ruggedness and sublimity.

In general, Hudson River School artists believe that nature in the form of the American landscape is an ineffable manifestation of God, though the artists varied in the depth of their religious conviction.

They take as their inspiration such European masters as Claude Lorrain, John Constable and J. M. W. Turner.

Their reverence for America's natural beauty is shared with contemporary American writers such as Henry David Thoreau and Ralph Waldo Emerson.

Several painters are members of the Düsseldorf school of painting, others have been educated by the German Paul Weber.

While the elements of the paintings are rendered realistically, many of the scenes are composed as a synthesis of multiple scenes or natural images observed by the artists.

In gathering the visual data for their paintings, the artists travel to extraordinary and extreme environments, which generally have conditions that will not permit extended painting at the site.

During these expeditions, the artists record sketches and memories, returning to their studios to paint the finished works later.

The second generation of Hudson River school artists had emerged to prominence after Cole's premature death in 1848; its members include Cole's prize pupil Frederic Edwin Church, John Frederick Kensett, and Sanford Robinson Gifford.

Works by artists of this second generation are often described as examples of Luminism.

In addition to pursuing their art, many of the artists, including Kensett, Gifford and Church, are among the founders of the Metropolitan Museum of Art in New York City.

Most of the finest works of the second generation are painted between 1855 and 1875.

During this time, artists such as Frederic Edwin Church and Albert Bierstadt are celebrities.

They are both influenced by the Düsseldorf school of painting, and Bierstadt had studied in that city for several years.

When Church exhibits paintings such as Niagara or The Icebergs, thousands of people pay twenty-five cents a head to view the solitary works.

The epic size of these landscapes, unexampled in earlier American painting, remind Americans of the vast, untamed, but magnificent wilderness areas in their country.

Such works are being painted during the period of settlement of the American West, preservation of national parks, and establishment of green city parks.