The following websites offer images that are either public domain or have very generous usage rights. Be sure to read usage terms at each site. We call them “free” as they were paid for with U.S. tax dollars (which means they are now free to use).

• Center for Disease Control- Public Health
• CIA World Fact Book
• Creative Americans 1932 – 1964
• Images of American Political History
• Library of Congress
• NASA Earth from Space
• NASA Visible Earth
• National Park Service Digital Image Archive
• NOAA Photo Library
• US Army Corps of Engineers Digital Visual Library
• US Air Force Link
• US Antarctic Program
• US Department of State
• US Fish & Wildlife Services
• US Government Image Portal
• US Navy
• USDA Agricultural Research Service
• USDA