Before the Presidential Records Act of 1978, all presidential papers were considered the personal property of the president, and presidents took their papers with them when they left office. The Presidential Records Act of 1978 designated any document produced during the course of the president's official duties (by both the president and his or her staff) as official, public records, and as such those documents become the property of the nation. Since 1981 each departing president has been required to deposit any such records with the National Archives and Records Administration.
The Presidential Records Act obviously does not apply to most American presidents. The papers of pre-Reagan American presidents exist in varying states of completeness, and some no longer exist at all. Many were subsequently acquired by the Library of Congress, and they have made the papers of several nineteenth century presidents available online. Some are still only available on microfilm.
Bear in mind that these "presidential papers" will include a mixture of personal and official papers.
Listed here are those presidential papers that we have in our collection here at University of Illinois. Papers of other presidents not listed might be available through interlibrary loan, and we likely have guides to those papers.
Unpublished U.S. government documents are acquired, organized, and stored by the National Archives and Records Administration (NARA). The NARA, as the name suggests, is an archive, and organizes documents, like other archives, by provenance. In the case of the NARA, provenance generally means originating agency. The government agency responsible for conducting diplomatic relations with foreign governments is the State Department. Records of the State Department can be found in Record Group 59. Learn more about the organization of State Department records (which has changed over time) here. The agency responsible for waging war against other nations has changed over time: the War Department became the Department of Defense in 1949. All these agencies fall under the Executive Branch.
Published documents are distributed to libraries through the Federal Depository Library Program, and can be identified using the Monthly Catalog of United States Government Publications (see entry under Reference Sources > Bibliographies, Catalogs, and Guides), and also through library catalogs.
Below are some collections of both published and unpublished documents: