Legislative history can provide insight into the intent of a law through examination of bills, committee hearing transcripts, committee hearing reports, congressional debates, and other documents such as committee prints or presidential messages. Before beginning the legislative history research, it is important to identify the law by its public law citation or its Statutes at Large citation (e.g. P.L. 107-110; 30 Stat. 750) as well as its bill number and the Congress of the Act or Resolution (e.g. H.R. 1 from the 107th Congress). If you have the popular name of the statute (e.g. No Child Left Behind) you can often find this information through a web browser.
From the Government Printing Office, GovInfo provides full-text searching of the US Code, Code of Federal Regulations, the Federal Register, and the Congressional Record. It also included federal court opinions back to 2004.
Congress.gov is the official website for U.S. federal legislative information. The site provides access to accurate, timely, and complete legislative information for Members of Congress, legislative agencies, and the public. It is presented by the Library of Congress (LOC) using data from the Office of the Clerk of the U.S. House of Representatives, the Office of the Secretary of the Senate, the Government Publishing Office, Congressional Budget Office, and the LOC's Congressional Research Service.