The Cabinet of the United States is composed of the most senior appointed officers of the executive branch of the federal government of the United States, who are generally the heads of the federal executive departments.
The existence of the Cabinet dates back to the first President, George Washington, who appointed a Cabinet of four people to advise him and to assist him in carrying out his duties (his cabinet also included Vice President John Adams):
Secretary of State Thomas Jefferson
Secretary of the Treasury Alexander Hamilton
Secretary of War Henry Knox
Attorney General Edmund Randolph
Postmaster General Samuel Osgood
(This office did not become part of the Cabinet until 1829)
All Cabinet members are nominated by the President and then presented to the Senate for confirmation or rejection by a simple majority (although, before use of the nuclear option during the 113th US Congress, they could have been blocked by filibuster, requiring cloture to be invoked by 3⁄5 supermajority to further consideration). If approved, they are sworn in and then begin their duties. Aside from the Attorney General, and the Postmaster General when it was a Cabinet office, they all receive the title of Secretary.
Members of the Cabinet serve at the pleasure of the President; the President may dismiss or reappoint them (to other posts) at will.