U.S. Government documents provide a rich source for primary source material for the study of U.S. history. Falling into the broad category of anything published or created by a government entity, these cover almost every subject and date from the origins of our country to the present day.
The Public Papers of the Presidents have been published for every president since Herbert Hoover in 1929. The volumes contain a compilation of speeches, press conferences, public messages, etc. Executive orders and proclamations were not regularly included until 1977 (beginning with the Jimmy Carter administration), the sources below include an archive of these documents.
Foreign Relations of the United States (FRUS) contains important diplomatic and intelligence communications between U.S. officials and between the U.S. and other countries. It is considered the official record of major U.S. foreign policy decisions, but are generally published about 30-35 years after events because of the sensitive nature of the documents included. FRUS volumes currently cover 1861-1980.
here are many records and papers produced by agencies that never get released. They are not actually classified they are just considered internal departmental documents and are therefore not published. Records like these as well as other published and classified documents eventually end up at NARA. Although NARA puts select material online, there is even more material that is available only on microfiche or at one of the National Archives locations.