The National Security Archive contains declassified US documents obtained through the Freedom of Information Act. The Archive is also a research institute on international affairs, a library, a public interest law firm defending and expanding public access to government information through the FOIA, and a publisher.

"National Security Archive Electronic Briefing Books provide online access to critical declassified records on issues including U.S. national security, foreign policy, diplomatic and military history, intelligence policy, and more. Updated frequently, the Electronic Briefing Books represent just a small sample of the documents in our published and unpublished collections."

Also use Digital National Security Archive that contains contemporary declassified national security primary source documents digitally published thematically by Chadwyck-Healey.

For a collection of similar materials collected by the various presidential libraries also see the Declassified Documents Reference System.