The United States Antarctic Program is home to thousands of photos available (complete with captions, credits and resolutions) for you to view and use. They even welcome contributions.
David Rumsey Historical Map Collection (1536 px) The David Rumsey Historical Map Collection contains to date over 10,000 maps online and focuses on rare 18th and 19th century North and South America cartographic history materials. Historic maps of the World, Europe, Asia and Africa are also represented.
Image Database to Enhance Asian Studies (1700 px) A searchable image database with a wide variety of historic images of asia. Great for people, places and artifacts.
Library of Congress American Memory Today in History mines the American Memory historical collections to discover what happened in American history today…and every day.
Maps Collections MAPS!, Military Maps! Panoramic Maps! Even maps of maps. There’s puns of maps and this site marks the spot.
NRCS Photo Gallery The NRCS Photo Gallery contains complimentary natural resource and conservation related photos from across the United States. Use drop-down menu to search. Photos in the Gallery are available in TIFF or JPEG. Image resolution is generally 1500 × 2100 pixels (5” x 7” at 300 dpi).