The United States Code is the codification by subject matter of the general and permanent laws of the United States. It is divided by broad subjects into 54 titles and published by the Office of the Law Revision Counsel of the U.S. House of Representatives.
The Code of Federal Regulations (C.F.R) is the codification of the general and permanent rules published in the Federal Register by the departments and agencies of the Federal Government. It is divided into 50 titles that represent broad areas subject to Federal regulation. The 50 subject matter titles contain one or more individual volumes, which are updated once each calendar year, on a staggered basis
The Federal Register (Fed. Reg.) is the official daily publication for rules, proposed rules, and notices of Federal agencies and organizations, as well as executive orders and other presidential documents.
Legislative history can be extraordinarily 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.