The congressional material in the U.S. Serial Set includes the committee reports, journals, manuals, and administrative reports of both Chambers in addition to a variety of directories, orations, and special publications (such as illustrated descriptions of the Capitol). Unfortunately, not all these categories appear consistently in the Set.
Committee reports on proposed public and private legislation are among the most important of the U.S. Serial Set's congressional publications and have always been part of the Set. The journals of proceedings of both Houses appeared from the beginning but have been excluded from the Set since 1953, while Senate and House manuals did not appear in it until 1896, but are still included. The Congressional Directory was privately printed and distributed until 1865, and was not given serial numbering until 1882. Orations and eulogies have always appeared, but recently, addresses on deceased Members of Congress have been printed for distribution outside the U.S. Serial Set scheme.
Administrative reports of the Secretary of the Senate have always been provided with serial numbering, while in the last 30 years the reports of the Clerk of the House of Representatives sometimes have not. The Congressional Record and its predecessors (Annals of Congress, Register of Debates, Congressional Globe) have never been included. Texts of bills and resolutions are included in U.S. Serial Set publications sporadically and on an inconsistent basis.
As a rule, committee hearings and prints have been considered committee rather than congressional publications and have consequently been excluded. Occasionally, however, hearings are printed as or included in U.S. Serial Set publications.
The Senate frequently sat in secret session in early Congresses and proceedings and other records of such sessions (executive journals, executive documents, and executive reports) were not included in the Set except by special order. These types of executive publications should not be confused with executive branch publications that did appear in the U.S. Serial Set with great frequency, especially in the earlier years.
Source: ProQuest Congressional
For more information see U.S. Congressional Serial Set: What It Is and Its History via GPO Access.
Although not part of the original serial numbering scheme, a publication of records from the early Congresses was numbered 001-038 when shelved in the Public Documents Library and has since generally been considered a part of the Serial Set.
This publication, the American State Papers, was privately produced under congressional authority between 1832 and 1861. It included records that were previously available only in manuscript, as well as printed executive and legislative documents. The series covers a period starting at 1789 and ending with dates varying between 1823 and 1838.
Source: National Archives
Congressional documents originate from congressional committees and cover a wide variety of topics and may include reports of executive departments and independent organizations, reports of special investigations made for Congress, and annual reports of non-governmental organizations. Congressional documents, along with Congressional reports, are part of the U.S. Congressional Serial Set, commonly referred to as the Serial Set.
Congressional reports originate from congressional committees and deal with proposed legislation and issues under investigation. There are two types of reports:
House and Senate Reports: Reports of congressional committees concerning proposed legislation and/or contain findings on matters under investigation.
Senate Executive Reports: Reports of the Committee on Foreign Relations relating to treaties between the United States and foreign nations which have been submitted to the U.S. Senate for ratification, or are reports of various Senate committees regarding nomination of individuals.