For document availability by date and by source, see this chart.
Whether or not they are adopted, amendments are reproduced in the Congressional Record.
The full text of bills is available from several different sources, depending on the date of the bill and the format required. A bill may have many different versions, and it’s important to have the correct version of the bill when reading accompanying documents, like reports and debate.
Online sources for bills are listed below. See also the Chart - Sources for Legislative Documents.
Provides access to Legislative Histories (1969-present); Congressional Reports (1817-present); Congressional Hearings (published and unpublished) (1824-present); U.S. Congressional Serial Set and American State Papers from 1789-1969; and CRS Reports (1916-present). Also contains member biographies, committee assignments, voting records, and financial data
Additional sources for bills:
Microfiche: The library has two sets providing coverage from the 91st Congress (1969) to the 95th Congress (1978), and from the 96th Congress (1979) to the 110th Congress (2008).
Law Library of Congress: copies of bills older than 1969 and not otherwise available may be obtained in person at the Law Library of Congress.