The United States Government Manual

The directory provides comprehensive information on the agencies of the legislative, judicial, and executive branches, as well as quasi-official agencies, international organizations in which the United States participates, boards, commissions, and committees.
Each agency’s description consists of the following:
– List of principal officials
–Summary statement of the agency’s purpose and role in the Federal Government
–Brief history of the agency, including its legislative and executive authority
–Description of consumer activities, contracts and grants, employment, and publications