The National Security Archive

The National Security Archive is an independent non-governmental research institute that collects and publishes declassified documents. The Archive also serves as a repository of government records on a wide range of topics pertaining to the national security, foreign, intelligence, and economic policies of the United States. Archive staff members systematically track U.S. government agencies and federal records repositories for documents that either have never been released before, or that help to shed light on the decision-making process of the U.S. government and provide the historical context underlying those decisions.

http://nsarchive.gwu.edu/