Legislative history is useful for determining the intent behind a law, whether you're trying to determine why the law was changed or what Congress meant by a specific phrase. Legislative history is typically found in documents created during the legislative process, including reports, hearings, records of debates, and different versions of the bill.
Legislative history is a primary source that provides guidance, but it should not be cited as legal authority. Courts can only look to the legislative history of a statute to “explain the meaning and purpose of a provision whose text is genuinely ambiguous.” Sherfel v. Newson, 768 F.3d 561, 569 (6th Cir. 2014). The documents of legislative history for tax law research purposes are listed below:
1. Congressional Committee Reports / Conference Reports
2. Text of earlier or alternative versions of a bill
3. Floor Debates (Congressional Record)
4. Statements or testimony at Committee Hearings
5. Committee Prints
6. Presidential Signing Statements
United States Code Congressional & Administrative News (USSCAN) by The 1954 and 1939 Internal Revenue Codes are available on Westlaw.