Legislative history is a term that refers to the documents that are produced by Congress as a bill is introduced, studied, and debated. These legislative documents are often used by attorneys and courts in an attempt to determine Congressional intent or to clarify vague or ambiguous statutory language. Note, however, that legislative documents are merely persuasive authority, not mandatory authority. (You can learn more about the legislative process and how to use legislative history documents for statutory interpretation by referring to a treatise on the topic.)
The legislative process that produces the documents discussed in this guide can be quite complex, but a basic understanding of this process is crucial to understanding how to do legislative history research (and how to use different types of legislative history documents in your writing). Refer to this page of our guide to learn more about the federal legislative process.
This guide will first discuss each of the types of documents that come out of the legislative process and their use, and will then set out methods of locating each. Refer to the Quick Reference Chart for a fast guide to sources for each major type of legislative history document.
This guide focuses primarily on the law-making functions of Congress; for a focus on Congressional investigations, refer to our Congressional Investigations Research Guide.
Committee Reports are usually considered the most important legislative documents and contain more analysis than the other documents. Bill versions and Congressional Debates may also be relevant. The other legislative materials typically provide little information that would help you to determine legislative intent, although they often provide valuable background and factual information on the issue being addressed by the legislation.
See each sub-page of this guide for more information on each type of document.
Legislative documents are typically numbered in sequence contextually to the year or legislative session in which that document was produced. (E.g. "H.R. 1" would generally be the first bill introduced in the House of Representatives for that session of Congress; the next session, and every other session, there would be a new, different "H.R. 1".) Therefore, you usually must include the year or session of Congress when you cite to a legislative document or when you are looking to find a particular document by its citation. (E.g. "H.R. Rep No. 105-452" indicates report 452 issued in the House of Representatives during the 105th Congress.)
If you are unsure about which Congress or year your law was passed, you may find it helpful to use the table of Years of Congress Conversion Table.