The Library of Congress
Gateway to rich primary source materials relating to the history and culture of the United States.
The site offers more than 5 million items from more than 90 historical collections - including these selected image collections:
The ARTstor Digital Library is comprised of digital images and related data and the tools to make active use of those images. The Collection contains approximately one million digital images of visual material from different cultures and disciplines.
The collection documents artistic traditions across many times and cultures and embraces such topical areas as: architecture, garden and landscape, decorative arts, painting, sculpture, photography, and design -- as well as many other forms of visual culture.
ARTstor contains the following topical collections:
Additionally, ARTstor has images of some of the work by such land/environmental artists such as: Andy Goldsworthy, James Turrell, Beverly Pepper, Nancy Holt, Robert Smithson, Michael Heizer, Alan Sonfist, et al.