CyberCemetery . An archive of the web sites and publications of defunct federal agencies. Sites appear as they did at the time each agency closed, 1995-present.
Foreign Relations of the United States, 1863-1958. From the University of Wisconsin-Madison Libraries. Full text of the FRUS papers for some volumes from these years. (Collection is incomplete.) Does not including documents dealing with World War I and the Russian Revolution.
NARA. Official website of the National Archives and Records Administration. Search feature enables user to identify archival collections as well as the full-text or PDF facsimiles of documents from the CIA and other government agencies.
National Security Archive. An independent library at George Washington University. More declassified documents pertaining to U.S. foreign relations.