The Long 19th Century. Paul Halsell's Modern Sourcebook. Great place to start for primary sources and for links to other solid sites. http://www.fordham.edu/halsall/mod/modsbook3.html

See also his documents and links for various aspects of the 20th century. http://www.fordham.edu/halsall/mod/modsbook.html

The Web Museum: paintings, with a solid selection of 19th and 20th century artists, and some useful descriptions of particular works of art, painters, and movements): http://www.ibiblio.org/wm/

Web Gallery of Art: http://www.kfki.hu/~arthp/welcome.html

Mark Harden's Artchive: an excellent selection of paintings organized by painter: http://www.artchive.com/core.html

Directory of Museums: access to museums on the Internet: http://icom.museum/vlmp/

Artcyclopedia: paintings and description of works by movement, subject or artist: http://www.artcyclopedia.com/index.html

Modern Sourcebook: documents from the period. http://www.fordham.edu/halsall/mod/modsbook15.html

Romantic links: connects to electronic texts, to journals and associations dealing with Romanticism, to other general sites. http://www.english.upenn.edu/~mgamer/Romantic/

English Romanticism: material on both art and literature. http://www.uh.edu/engines/romanticism/

Impressionism: features the principal artists and their major works. http://art.koti.com.pl/index_en.html

Impressionism: a general introduction with a tour of the paintings. http://www.impressionism.org/

Art history: provides a number of links as well as basic information on key artists of this movement. Look here, for example, to find directions to sites focusing on Van Gogh. http://arthistory.about.com/cs/postimpartists/

Guggenheim: their collection of post-Impressionist paintings.
http://www.guggenheimcollection.org/site/movement_works_Post_Impressionism_0.html You can look up other movements as well. See, for example, Expressionism

Futurism: principal Futurist manifestos and links to other sites. http://www.unknown.nu/futurism/

Futurism and Futurists: claims to be the largest site, with numerous paintings, writings, and links. http://www.futurism.org.uk/

DaDa On Line: access to texts, a list of artists, and works of art--defines Dada broadly. http://www.peak.org/~dadaist/

International Dada Archive: a site organized by the University of Iowa library, this emphasizes bibliographical resources and original documents. http://www.lib.uiowa.edu/dada/

Surrealism Gallery: good selection of artists and their works, with music. http://www.mcs.csuhayward.edu/~malek/Surrealism/

What is Surrealism? André Breton's Manifesto. Also available at other sites on the Web. http://www.myism.com/what-is-surrealism.htm