NPS Historic Photograph Collection
The National Park Service Historic Photograph Collection is comprised of more than two million images which cover a wide variety of subjects: Park architecture, Civilian Conservation Corps (CCC), Native American heritage, NPS personnel, roads and transportation, scenic views, and much more.
PDPhoto.org is a repository for free public domain photos. Unless something is clearly marked as being copyrighted, you can assume it is free to use.
Prints & Photographs Online Catalog
The Prints & Photographs Online Catalog (PPOC) provides access through group or item records to more than 50% of the Division's holdings, as well as to some images found in other units of the Library of Congress. Many of the catalog records are accompanied by digital images--about one million digital images in all.
U.S. Government Photos and Multimedia
Most of these images and graphics are available for use in the public domain, and they may be used and reproduced without permission or fee. However, some images may be protected by license. We strongly recommend you thoroughly read the disclaimers on each site before use.