For official information about federal agencies, see the United States Government Manual. This publication provides information on the agencies of the legislative, judicial, and executive branches, as well as quasi-official agencies, international organizations in which the US participates, boards, commissions, and committees.
Appendix C is a listing of all terminated or transferred agencies.
To find contact information for federal agencies, use The Federal Yellow Book (Smith & Ref Coll JK 6 .F45).