Federal Legislative History

1. A U.S. Representative introduces a House bill (e.g. H.R. 2315) or a U.S. Senator introduces a Senate bill (e.g. S. 425).
    
2. The bill is assigned to a committee. The committee may let the bill die or hold hearings and mark up (amend) the bill. In the process, the committee may produce:
   1. Committee prints: Compilations of materials considered by the committee, such as draft bills and background reports prepared by legislative staff.
   2. Committee hearings: Transcripts and prepared statements delivered by witnesses at the hearing.
   3. Committee reports: Final reports expressing the committee's own opinions on the bill.
       
3. The bill is reported from committee and sent to the floor of its originating house for debate and voting. Once a bill passes in its originating house, it is called an engrossed bill.
    
4. The engrossed bill is sent to the other house and the same process begins again. Once it is sent to the other house, it is called an act.
    
5. If the two houses disagree on aspects of the bill, they may have a conference to resolve disputes and draft a conference report. Once the bill passes both houses, it is called an enrolled act.
    
6. The enrolled act is sent to the President, who will either sign or veto it, often with an accompanying signing or veto statement. Once the bill has become law, it is called a statute.
    
7. The statute is assigned a public law number (e.g. Pub. L. 93-406) and published by date in the official Statutes at Large (Stat.) and Westlaw's unofficial U.S. Code Congressional and Administrative News (U.S.C.C.A.N.). USCCAN may also publish presidential statements, complete or excerpted committee reports or conference reports, and citations to other legislative history documents.
    
8. Current statutes are organized by topic in the official United States Code (U.S.C.). Westlaw and Lexis take the basic text of the U.S.C. and add annotations (notes explaining each statute's history and identifying relevant cases and secondary sources interpreting the statute) to produce Westlaw's unofficial United States Code Annotated (U.S.C.A.) and Lexis' unofficial United States Code Service (U.S.C.S.).

Click to view a larger version. CC-BY 3.0 Mike Wirth & Dr. Suzanne Cooper Guasco, How Our Laws Are Made, https://commons.wikimedia.org/wiki/File:Visualization-of-How-a-Bill-Becomes-a-Law_Mike-WIRTH.jpg. 

A legislative history of a bill is the sequence of steps or path taken to arrive at the final version of the law; the term is also used to refer to the documents reflecting that history.  One of the purposes in compiling a legislative history is to try to ascertain what the legislature intended in authoring the bill, or the purpose and meaning of specific legislative language.  

Different types of legislative history are given different weight.

Committee reports are generally given the most weight in determining legislative intent, because they are produced by the committee to which Congress has delegated the responsibility for detailed study and recommendation. Especially significant are Conference Reports, produced by Conference Committees appointed by the House and Senate to negotiate differences between House and Senate versions of a bill.

Changes of language in the bill as it is amended are given high significance.

Other documents, though less valuable than reports or the variant text of bills, may shed light on the context in which legislators considered the bill in question:

• Legislative debates in the Congressional Record may include statements by a bill’s sponsors or the chairs of the committees considering the bills, which are given more weight than comments by Representatives or Senators not involved with the specific bill.  However, statements may be contradictory (making it difficult to infer the intent) and can be altered prior to publication. 
• Hearings must be used critically since testimony includes both that of disinterested experts and highly partisan interest groups. 
• Committee prints are prepared by committee staff for use by legislators; as such, they cannot reflect intent, but nonetheless can be enlightening. 
• House and Senate Documents (available in the Serial Set) often consist of executive reports and proposals which may be useful for understanding bills proposed by the executive branch.