National Security Council
Created by the National Security Act of 1947, the National Security Council (NSC) was intended to be the top-level committee for planning the overall foreign and military policy of the United States. The NSC proper was not intended to be a large independent organization; it would have an Executive Secretary and a small staff. With the exception of the Assistant to the President for National Security Affairs, all other NSC members would be either elected officials, or appointed by the President and confirmed by the Senate.
The original voting members were the President, Vice-President, Secretary of State, Secretary of Defense, Assistant to the President for National Security Affairs, and the Director of the Office of Emergency Planning. The last function changed several times, becoming the Federal Emergency Management Agency in the Executive Office of the President. With the formation of the Department of Homeland Security, FEMA was absorbed and lost its effective cabinet status.
In the original legislation, the Director of Central Intelligence and the Chairman of the Joint Chiefs of Staff were named as statutory advisors. There was no real restriction on the President having other people as members or advisors; voting was really not a major issue, given the President would always have the final vote. Various Presidents have had the Attorney General, Secretary of the Treasury, and Secretary of Energy meet with the NSC.