U.S. Government Archives
National Archives
Records in the National Archives are organized into Record Groups, largely based on government departments (Dept. of State is RG 59; FBI is 65). Each record group is broken down into numerous series and subseries. A useful orientation to the structure of the records in your area can be gained by browsing the Guide to Federal Records (online and in print HOLLIS Records; HathiTrust ; NARA ). The record groups are listed here https://www.archives.gov/records-mgmt/rcs/schedules/list-all-record-groups. Switch to Organization Name for an alphabetical list of departments.
Search for records of interest in the NARA catalog https://www.archives.gov/research. In Advanced Search you can limit to digitized records which comprise a huge number of records, but a minute fraction of the whole Archives.
Numerous NARA archival collections have been microfilmed. These are listed in the NARA Microfilm Catalog Many of these are available in the Harvard Library. Those not held by Harvard may often be found in WorldCat and obtained via Interlibrary Loan. Many reel guides for NARA microfilm are available in HathiTrust.
Microfilm Publications and Original Records Digitized by Our Digitization Partners: Ancestry, Fold3, FamilySearch. National Archives.
Electronic Reading Rooms of US government departments are listed on the FOIA site. Scroll down to View the full list of agencies and choose your agency. Under Select an Office, choose the office of the Secretary or equivalent central office.
Digitized material outside of the NARA website
U. S. Declassified Documents Reference System Online which contains declassified documents sent from various government agencies to the presidential libraries.
Some material on the Presidential Library websites is not in the Declassified Documents Reference System.
Digitized and microfilm national security and foreign relations material, together with presidential material, is https://guides.library.harvard.edu/foreignrelations is available via the Library Research Guide for U.S. Foreign Relations
Declassified Documents
The National Archives and Record Administration (NARA) routinely reviews 25-year old files in many record groups for declassification. Some of this material is microfilmed and some of the microfilm is offered for sale by commercial vendors (See below). Since the 1966 Freedom of Information act (FOIA), declassification of more recent documemts can be requested by individuals. Also, many government agencies have FOIA Electronic Reading Rooms on their websites.
The two most important collective sources for FOIA material are:
Digital National Security Archive (1945- ) contains 22 core collections of declassified documents, previously published on microfiche. Additional material is available in their Electronic Briefing Books and the CIA’s “family jewels” collection
U. S. Declassified Documents Reference System Online which contains declassified documents sent from various government agencies to the presidential libraries.
Some material on the Presidential Library websites is not in the Declassified Documents Reference System.
Major Electronic Reading Rooms include:
CIA Electronic Reading Room If you leave the search field blank and hit search, you can use the filters on the right to narrow your search. CREST (CIA Records Search Tool) material as well as FOIA is included. Also:
CIA's Analysis Of The Soviet Union, 1947-1991
State Department Electronic Reading Room contains over 50,000 documents. State Department material from 1973-76 is available on the National Archives’ Access to Archival Databases website.
Department of Defense FOIA Reading Room
OpenNet via Department of Energy
IRS Electronic Reading Room. FOIA information
Other Electronic Reading Rooms are listed on the FOIA site. Scroll down to View the full list of agencies and choose your agency. Under Select an Office, choose the office of the Secretary or equivalent central office.
Other Sources
Official Intelligence Agency Homepages (Federation of American Scientists)
Pentagon Papers, officially titled "Report of the Office of the Secretary of Defense Vietnam Task Force"
Project on Government Secrecy (Federation of American Scientists)
Commercial Microfilm
Most of the National Archives microfilm is distributed by the following companies. You can browse or search their microfilm lists, and then look up the microfilm in HOLLIS or WorldCat.
Primary Source Media, Scholarly Resources, University Publications of America (ProQuest)
Finding HOLLIS records for a group of microform collections (as opposed to a known item search for a single collection) presents difficulties. An inclusive search on “United States State Department” yields 6516 records. There are several possible limitations which narrow the results, but each has problems:
1. Limit to Library: Microforms (Lamont), but this misses collection at the Center for Research Libraries (CRL), easily obtainable via Interlibrary Loan.
2. Limit to Format: Microforms, but some microform records made before about 1980 were not tagged as microform.
3. Add the terms Sources or Archives or Correspondence to the search.
4. Gather terms (e.g., despatches, "Central files” “special files” “post records”) from your results to add to searches.
A combination of various searches with browsing in the above research guides and publishers’ lists is best.