Birds of the World: 250 Years of Color Plate Folios
Exhibition held at the McClung Museum in 1997 presented bird illustrations from a variety of artists.
http://mcclungmuseum.utk.edu/specex/birds/birds.htm

Illustration Cupboard
London gallery of original artwork.
http://www.illustrationcupboard.com/

National Museum of American Illustration
The artwork from the golden age of American illustration.
http://www.americanillustration.org/

Norman Rockwell Museum
Original Norman Rockwell art located in Stockbridge MA.
http://www.nrm.org/

The Illustrated Gallery
(Philadelphia, PA) Gallery with large collection of illustrated art.
http://illustratedgallery.com/

UK Illustrators Showcase and Gallery
Showcase of UK line-art illustrators and watercolorists.
http://www.artsweb.co.uk/