This link now goes to the new Congress.gov website, which replaces Thomas. This site provides access to federal legislative information such as: Bills, resolutions, activities in Congress, roll call votes (and more), schedules, calendars, committee reports, etc.
This system has the full text of many U.S. Federal Government documents, including the Federal Register, the Code of Federal Regulation, Congressional bills, reports and hearings, the U.S. Code, and U.S. court opinions. This site is the official electronic version of these texts.
"The Congressional Research Service (CRS) does not provide direct public access to its reports, requiring citizens to request them from their Members of Congress. Some Members, as well as several non-profit groups, have posted the reports on their web sites. This site is not affiliated with the Congressional Research Service, but aims to provide integrated, searchable access to many of the full-text CRS reports that have been available at a variety of different web sites since 1990." - UNT Digital Library
The Library of Congress is the nation's oldest federal cultural institution, research library of the United States Congress, and de facto national library of the United States. It is also the largest library in the world, with millions of books, recordings, photographs, maps and manuscripts in its collections.
Congressional Journals, Annals, and Statutes from 1774 to 1873. It does not appear that the full text of items available only in GIF format is indexed, but the full text of HTML pages is indexed for searching.