Art Images for College Teaching
This collection contains images of art and architectural works within the public domain as specified by US law.

Historical Images (Canada)
A number of institutions in Canada permit use of images for educational puposes. Most require students to write a credit line below the image. This link takes you to a separate page that lists some of these instituttions.

Life Photo Archive"Search millions of photographs from the LIFE photo archive, stretching from the 1750s to today. Most were never published and are now available for the first time through the joint work of LIFE and Google." Searchable by keyword, or browse by decade (1860s to 1970s) or featured people, places, events, sports, and culture. From Google.

NASA
NASA images are generally not copyrighted. Most images are availailable for educational use. Note that the NASA logo is copyrighted!

NRCS Photo Gallery(from the U.S. Department of Agriculture)
The NRCS offers free use of their images. The photos cover a range of topics from artwork to woodland habitats. Citation requirements can be found by scrolling down the page.

Pics4Learning
Pics4Learning is a copyright-friendly image library for teachers and students. The site offers thousands of images -photos and graphics- for educational use.

Smithsonian Institue
The Smithsonian allows use of images for educational purpose. Users must cite the author and source of the content. Copyright information and the Smithsonian URL must be cited. Works cannot be modified.