GovEngine.com

This well organized, browsable directory, maintained by a Florida nonprofit, consolidates links to official federal, state and local government information sites for the United States, Guam,  American Samoa, Virgin Islands, and the Commonwealth of the Northern Mariana Islands.  Browse by type of government--federal, state, or local--or by state.  The local government section includes links to official county and city Web sites.

FedStats

The gateway to statistics from over 100 U.S. Federal agencies 

FedWorld

The FedWorld.gov web site is a gateway to government information. This site is managed by the National Technical Information Service (NTIS) as part of it's information management mandate.

FirstGov
The only official U.S. Government portal to 30 million pages of government information, services, and online transactions; it offers "a powerful search engine that searches every word of every U.S. government document in a quarter of a second or less." Browse according the subject of information you desire.

Info USA
Information about many agencies and departments of the U.S. government, produced and maintained by the U.S. Department of State.  Created for foreign audiences seeking information about American society, political processes, official U.S. policies and culture, but useful for all as an accurate source of data and information.

Ben's Guide to American Government for Kids (Grades 9-12)
Find out here about the various agencies and services of the U.S. Government. The guide provides learning tools for K-12 students, parents, and teachers. These resources will teach  how our government works, the use of the primary source materials of GPO Access, and how one can  use GPO Access to carry out their civic responsibilities. 

C-SPAN Congressional Glossary
Are you wondering about the meaning of some of the terminology associated with the U.S. Congress? This glossary allows you to click on any term used in Congress to see its definition.

Historical United States Census Data Browser
The data presented here describe the people and the economy of the US for each state and county from 1790 to 1960. Data is accessible and organized into decades for most of the time periods.

US Census Bureau
The provider of timely, relevant, and quality data about the people and economy of the United States.