The United States federal executive departments are among the oldest primary units of the executive branch of the federal government of the United States—the Departments of State, War, and the Treasury all being established within a few weeks of each other in 1789.

The heads of the federal executive departments are the members of the traditional Cabinet; since 1792, they have, by statutory specification, constituted a line of succession, after the Speaker of the House and the president pro tempore of the Senate to the presidency in the event of a vacancy in both that office and the vice presidency. The Constitution refers to these officials when it authorizes the President, in Article II, section 2, to "require the Opinion, in writing, of the principal Officer in each of the executive Departments, upon any Subject relating to the Duties of their respective Offices." In brief, they and their organizations are the administrative arms of the President.

• Military@ (8)

• Central Intelligence Agency@ (4)
• Federal Bureau of Investigation@ (8)
• National Counterintelligence Information Center@ (1)

• National Imagery and Mapping Agency@ (1)
• National Reconnaissance Office@ (1)
• National Security Agency@ (1)

See also:

• Society: Government: Intelligence (36)

• President's Intelligence Advisory Board (PIAB)
  whitehouse.gov
  Along with its component Intelligence Oversight Board (IOB), provides advice to the President concerning the quality and adequacy of intelligence collection, of analysis and estimates, of counterintelligence, and of other intelligence activities.
• Intelligence Resource Program
  fas.org
  Federation of American Scientists have collected news, reports, documents, and web resources related to the US intelligence organizations, reform, oversight.
• OSINT
  groups.yahoo.com
  Maintained by The Intelligence Network, this is a high traffic list dedicated to the open sharing of any and all open source intelligence.