The United States Congressional Serial Set or "Serial Set" is a core U.S. government publication. Started in 1817, the Serial set contains House and Senate Reports and other Congressional documents, including documents sent to Congress by the President. Starting in 1979, the Serial Set also includes U.S. treaties. For a good discussion of the Serial Set and its indexes, see An Overview of the U.S. Congressional Serial Set by Rick McKinney (scroll down below the Schedule of Volumes).
The print Serials Set is available in Federal depository libraries. You can find local depository libraries through the Federal Depository Library Directory. Note: The government documents section of all Depository libraries must be open to the public (by law) during normal business hours, even if the rest of the library isn't.
Lexis has an electronic edition of the Serial Set covering 1970-present (LEGIS;SERST2).
Lexis also has Serial Set archive Lexis covering 1777-1969 (LEGIS;SERSET), which includes documents from the predecessor publication, the American State Papers.
Much of the contents of the Lexis electronic Serial Set is also available on ProQuest Congressional, which can be accessed through many academic and membership law library web sites. The current edition (1970-present) is available with the basic ProQuest Congressional subscription. The U.S. Serial Set Digital Collection, covering Congressional Reports and Documents from 1789 to 1969, is sold as an add-on module.
The Library of Congress U.S. Serial Set page links to selected Documents and Reports from the 23rd Congress (1833-1835) to the 64th Congress (1915-1917).
The Readex digital U.S. Congressional Serial Set covers 1817-1994 and includes a substantial subject index (subscription only).
Predecessor Publication: Before 1817, Congressional materials were published in the American State Papers.