Legislative history refers to the process that a piece of proposed legislation goes through before it becomes law and consists of the documents created during that process. Legislative history research is often conducted to investigate why Congress passed a particular law or to assist scholars, lawyers, and judges in interpreting a law.
Additional federal legislative history guides:
For major pieces of federal legislation, an exhaustive legislative history may have already been compiled by a scholar or legal practitioner and published. The following sources list published legislative histories by popular name and/or public law number. You may also locate compiled legislative histories using the ASU Libraries Catalog.
Proquest Legislative Insight (on campus or ASURITE)
Lists of Congressional publications associated with a public law, searchable by keyword, public law number, bill number, and Statutes at Large citation.
HeinOnline – U.S. Federal Legislative History Library (on campus or ASURITE)
Includes full-text legislative histories on important and historically significant legislation, texts related to legislative histories, and Sources of Compiled Legislative Histories: A Bibliography of Government Documents, Periodical Articles, and Books by Nancy P. Johnson.
Law Librarians’ Society of Washington, D.C. – Legislative Histories of Selected U.S. Laws on the Internet
This page from the Law Librarians' Society of Washington, D.C. links to free and commercial legislative histories arranged by popular name and public law number.
Department of Justice – Legislative Histories Created by the Department of Justice
A collection of legislative histories compiled by U.S. Department of Justice Library Staff. The legislative histories include some, or all, of the following: the Public Law; House and Senate Documents; House, Senate, and Conference Reports; House and Senate Committee Hearings; Congressional Debates (Congressional Record); related Bills; and Presidential Signing Statements.
Federal Legislative Histories: An Annotated Bibliography and Index to Officially Published Sources (1994)
This book gives information on federal legislative histories published by official sources for laws passed between the 4th Congress (1796) and the 101st Congress (1990).
Sources of Compiled Legislative Histories: A Bibliography of Government Documents, Periodical Articles, and Books, 1st Congress-114th Congress (2018)
This book gives information on compiled legislative histories published by official sources for laws passed between the 1st Congress (1789) to the 114th Congress (2016).
How Congress Passes Laws Now: 111th-116th Congress
This study by Villanova Law's John Cannan reviews how laws were passed based during the 111th-116th Congresses (2009-2020) and the information sources that were generated for each law. Downloadable spreadsheets provide information on committees that considered significant legislation, votes, reports, and more.
When no already compiled legislative history is available for the statute you are researching, you will need to gather the Congressional documents pertaining to that law yourself. Below are the steps in the federal legislative history research process.
Step One: Identify the public law number, Statutes at Large citation, and bill information of the enacting legislation
If you are starting with a U.S. Code citation, you will need to locate the public law numbers, U.S. Statutes at Large citations, and bill information for both the enacting legislation of that U.S. Code section and any amending legislation.
To do this, first locate the latest version of the code section you wish to research. Most sources for the U.S. Code include historical information which will be in a parenthetical at the end of each section. The parenthetical will list all public laws and corresponding Statutes at Large citations that added or amended the section. Historical notes at the end of the code section also provide details about what changes were made to the statute. Determine which amendments are relevant to your research and note the public-law number for each amendment.
Public law numbers are indicated by “P.L.” or “Pub. L. No.” and Statutes at Large citations are indicated by “Stat.” Bill information includes the bill number, either from the House of Representatives (“H.R.”) or Senate (“S.”) and the session of Congress in which the bill was considered (example: 107th Congress). Bill numbers for legislation from 1904-present are found on the first page of each statute as it appears in the Statutes at Large; to locate bill numbers for laws passed before 1904, use Eugene Nabors, Legislative Reference Checklist: The Key to Legislative Histories from 1789 to 1903, available on HeinOnline.
Step Two: Compare the enacted statute with the bill as introduced and any amendments
Proposed laws are introduced in Congress as bills or joint resolutions. As they go through the legislative process they can be changed many times. Compare the public law with the bill as introduced and with any amendments offered to see how the language changed. Changes that were made or rejected may give you an indication as to intent.
Resources for finding bills and amendments:
Resources for following the path the public law took through Congress:
Step Three: Locate congressional documents related to the bill(s) in question
As a bill moves through the lawmaking process a number of congressional documents are attached to it. These documents compose the legislative history of the bill and may include statements as to why the legislation was passed and/or the meaning of various elements of the legislation. The types of documents you should search for are listed below.
Conference and Committee Reports
Conference reports are frequently the best source of legislative intent because they represent the compromises made between the House and Senate and can include language which explains the intent of the legislation. Conference reports are numbered as either a House or Senate committee report, H.Rept. [Congress No.]-[Report No.], or S.Rept. [Congress No.]-[Report No.].
Hearings and Committee Prints
Hearings provide insight into what issues and questions the Committee considered important. Hearings frequently include expert testimony from citizens and interested parties. Hearings are not considered as important for determining legislative intent as Committee Reports.
Discussions on the House and Senate floors are available in the Congressional Record.
GovInfo, from the Government Publishing Office, provides free online access to official publications from all three branches of the Federal Government. Dates of coverage vary by resource.
Congress.gov, from the Library of Congress, is the official website for U.S. federal legislative information. It contains committee profiles, committee hearings and reports, the Congressional Record and Congressional Record Index, bill profiles, and executive communications for the years 1995-present.
Century of Lawmaking for a New Nation
This website, made available by the Library of Congress, contains U.S. congressional documents and debates for the years 1774-1875. It contains records and acts of Congress from the Continental Congress through the Forty-second Congress.
HeinOnline (on campus or ASURITE)
Provides image-based PDF images of both historic and current Congressional documents including the Congressional Record, CRS reports, and committee prints, as well as resources such as the Statutes at Large and compiled legislative histories.
ProQuest Congressional (on campus or ASURITE)
ProQuest Congressional provides access to federal legislative bills, statutes, committee hearings, committee reports, and voting history. Coverage varies by resource; 1789-present.
ProQuest Legislative Insight (on campus or ASURITE)
ProQuest Legislative Insight documents the legislative history of laws enacted by the U.S. Congress with links to relevant documents including the enacted public laws and related bills, Congressional Record excerpts, and committee hearings, reports, and documents. Coverage varies by resource; 1789-present.
Westlaw (Westlaw password required)
Westlaw provides access to a wide variety of tools and Congressional publications, including U.S. Code Congressional & Administrative News, the Congressional Record, bills, and statutes. Coverage varies by resource.
Lexis (Lexis password required)
Lexis also provides access to a wide variety of tools and Congressional publications, including the U.S. Serial Set (1777-present). Coverage varies by resource.