Searching for reliable historical information can be a difficult and time consuming process. Fortunately a great deal of information and guidance is available on the Internet, though not all of it is reliable. The best places to look first are the official websites of the historical organizations of the U.S. military, and the Library of Congress. Later you may also need to examine the websites of the National Archives and Records Administration and other organizations, as well as online library catalogs. Because information on the Internet is generally not comprehensive, it is likely that you will need to visit a library, and perhaps one or more archival facilities.
Unofficial Published Sources
Although almost all libraries and book stores contain books and magazines on U.S. military history, these range in quality from comprehensive coverage with excellent analysis, to severely biased and misleading hearsay and speculation. The researcher is cautioned to consult more than one book on a subject. Titles can be identified through online library catalogs and published bibliographies. Published book reviews and the opinions of librarians and subject experts can also help in the selection of books. Unless a book is a personal memoir, it should contain a section of acknowledgements, a bibliography, and hopefully, footnotes or endnotes referring to original documents and interviews, rather than simply other published books. If your local library does not own a needed book, you can request that they obtain it through interlibrary loan, or you can often purchase it from either new or used online book dealers.
Official Published Sources
Official histories, including published document collections, produced by the history offices of the armed forces and the State Department are generally very reliable sources. Even so, the cautious researcher will compare these books with academic books published by universities, or scholarly journals. Official histories are widely available in libraries, particularly U.S. Government depository libraries, and recently published books are typically available for sale from the U.S. Government Printing Office, or increasingly, from commercial publishers.
Locating Archival Documents
It is difficult to generalize about where original documents or records can be found. An ever growing body of them are being posted on the Internet, but due to the massive number of historic documents, financial and technological constraints, and in some cases, copyright restrictions, the majority of historic documents will probably never be available online. Thus to find these documents the researcher must become familiar with a variety of government organizations and offices.
In general, original unpublished U.S. military documents from World War II (1941-1945) or earlier are at one of the National Archives facilities. Researchers are cautioned that depending on the branch of service, documents from the Cold War-era may be held by the National Archives or still retained in archival collections at the historical facilities of the individual military services. Unfortunately there are no absolute rules for where documents are located. The thorough researcher will consult the National Archives and all likely military history organizations and offices. Published official histories and other scholarly books will often contain detailed information on where documents are located.
The National Archives and Records Administration includes two primary facilities in the Washington DC area, 15 regional branches , 10 presidential libraries, and two branches of the National Personnel Records Center. The two main facilities in the Washington, DC area consist of one at College Park, Maryland, which tends to have World War II and some Cold War records, and the downtown Washington DC facility that tends to have pre-World War II records. The regional branches hold the records of individual military installations and commands in their area such as naval stations or naval districts. Often, the records from several states are gathered at a single facility. The National Personnel Records Center's records are protected by the Privacy Act, which severely restricts the release of most personal information. Generally speaking, personnel records prior the 20th Century are at the National Archives in Washington DC, and later records are at the National Personnel Records Center.
Air Force History
The Air Force Historical Research Agency, the Air Force History Support Office, and the U.S. Air Force Museum websites are filled with useful information. The Air Force Historical Research Agency and the associated Air University Library, both at Maxwell Air Force Base, Alabama, are essential stops for those doing in-person research. Although holdings of documents at the Air Force History Support Office at Bolling Air Force Base in Washington, DC are extensive, researchers wishing to avoid eye strain from reading microfilm would do better to conduct their research at Maxwell Air Force Base.
The Army Center of Military History, U.S. Army Military History Institute, and The Institute of Heraldry, have useful websites with a great deal of online information. In-person researchers should make a point of visiting the U.S. Army Military History Institute at Carlisle Barracks, Pennsylvania. Although their collections are much smaller, the Army Center of Military History in Washington, DC is worth a visit.
Central Intelligence Agency
The Central Intelligence Agency's Electronic Document Release Center is an extremely useful source. It also contains links to collections of online declassified documents including the Bay of Pigs, prisoners of war and personnel missing in action, the shoot down of the U-2 aircraft piloted by Francis Gary Powers, analytic reports on the former Soviet Union, etc. Also of interest is the Center for the Study of Intelligence online publications, at http://www.foia.cia.gov/historical-collections. For in-person researchers, many declassified CIA documents are located in the national security files of Presidential libraries, and the National Archives in College Park MD where the records of the CIA’s predecessor organization, the Office of Strategic Services (OSS) are located.
Coast Guard History
The Coast Guard History office website is filled with useful information. Researchers may also wish to visit their office in Washington DC.
Defense Intelligence Agency
The Defense Intelligence Agency has posted a modest selection of online information including an intelligence chronology of the Persian Gulf War.
Department of Energy (nuclear testing documents)
Atmospheric nuclear testing typically involved personnel from all of the armed services. In some cases thousands of personnel and numerous warships, aircraft and vehicles were involved in individual tests. The Department of Energy (DOE) Human Radiation Experiments website contains useful information including 250,000 online historic documents from government agencies involved in nuclear testing. The DOE also maintains a document citation database to assist researchers of nuclear testing.
Joint Chiefs of Staff
The Joint Chiefs of Staff history office in the Pentagon has posted a collection of useful publications.
Marine Corps History
Although modest in size, the growing US Marine Corps History Division is a useful source of information. For the in-person researcher, the Division's offices have a wide range of archival collections ranging from unit command chronologies to oral histories. Though relatively small, their library is a valuable resource. The library of the Marine Corps University in Quantico, Virginia, is another valuable source.
National Reconnaissance Office
The National Reconnaissance Office has created a modest yet useful history page relating to the Corona spy satellite program.
National Security Agency
The National Security Agency's Center for Cryptologic History website contains useful information including declassified documents concerning the impact of signals intelligence on the Battle of Midway, the Cuban Missile Crisis, and other historic events.
The huge information-rich website of the Naval History and Heritage Command is the place to start all U.S. Navy history research projects. In addition to a Browse By Topic section designed to assist researchers, there is a "Wars and Conflict" section, a link to the Navy Department Library and its online library catalog, and information on the various offices of the Command. Offices of the Command have extensive holdings of archival records available for examination by in-person researchers. Perhaps the most useful publication of the Command is the Dictionary of American Naval Fighting Ships (DANFS).
State Department (foreign relations)
A vast number of declassified documents has been reproduced in the State Department's Foreign Relations of the United States series. Numerous volumes of this series are now online including ones on Vietnam, the Cuban Missile Crisis, the Arab-Israeli conflict etc.
National Security Archive (not a U.S. Government website)
Although not a U.S. Government organization, the National Security Archives, located at George Washington University in Washington, DC, has been nicknamed "the home of the Freedom of Information Act" by some researchers. A few of their valuable document collections are online. Of particular interest are documents on the Cuban Missile Crisis, the U.S. intelligence community, relations with China, nuclear weapons, and even the U.S. role in the death of Cuban revolutionary Che Guevera.