Reference: Washington Information Directory

This info is from 2002 however most of them would be still relevant: Congress: Senate: 

http://www.senate.gov House of Representativwes 

 http://ww.house.gov General Accounting Office 

http://www.gao.gov Library of Congress

 http://www.loc.gov White House: 

Executive Office of the President: 

 http://www.whitehouse.gov 

Government Departments: Agriculture: http://www.usda.gov 

 Commerce: http://www.doc.gov 

Defense http://www.defenselink.mil 

 Education 

http://www.ed.gov 

Energy: http://www.doe.gov 

 Health and Human services http://www.dhhs.gov

 housing and Urban Develpment http://www.hud.gov

 interior: http://www.doi.gov 

 Justice: http://www.usdoj.gov 

 Labor http://www.dol.gov 

State: http://www.state.gov 

Tranportation http://www.dot.gov 

 Treasury http://www.ustreas.gov 

veterans Affairs http://www.va.gov

 GOVERNMENT AGENCIES: Agency for Ingternational Development: http://www.info.usaid.gov 

Central Intelligence Agencyhttp://www.cia.gov 

Consumer Product Safety Commission http://www.cpsc.gov 

Environmental Protection Agency http://www.epa.gov 

Federal Communications Commission http://www.fcc.gov 

 Federal Deposit Insurance Corporation http://www.fdic.gov 

 Federal Election Commission http://www.fec.gov 

Federal Emergency Mangement Agency http://www.fema.gov 

 Federal Reserve System http://www.federalreserve.gov 

Federal Trade Commission http://www.ftc.gov 

Food and Drug Adminisration http://www.fda.gov 

General Services Administration http://www.gsa.gov 

National aeronautics and Space Adminstration http://www.nasa.gov National Archives and Records Administration http://www.nara.gov National Transportation Safety Board http://www.ntsb.gov Nuclear Regulatory Commission http://www.nrc.gov Pension Benefit Guaranty Corporation http://www.pbgc.gov Securities and Exchange Commission http://www.sec.gov Small Business Administration http://www.sba.gov smithsonian Institution http://www.si.edu social Security Administration http://www.ssa.gov US InformationAgency http://usinfo.state.gov US Postal Service http://www.usps.gov GOVERNMENT PUBLICATIONS OFFICES Consumer Information Center http://www.pueblo.gsa.gov Governmetn Printing Office http://www.gpo.gov National Technical Information Service http://www.ntis.gov