FedStats -- The gateway to the full range of official statistical information available to the public from over 100 U.S. Federal agencies. Information can be searched through an A to Z index or by keyword. Also contains "Statistical reference shelf" with links to tables from the Statistical Abstract and Federal Statistical Briefing Rooms, and others
GPO Access/FDsys -- Electronic access to the official published version of legislation and other information products produced by the Federal Government. No copyright restriction, unless specifically noted.
Thomas -- "In the spirit of Thomas Jefferson, legislative information from the Library of Congress, including a section on How Our Laws Are Made.