After the end of World War II, the Office of Strategic Services was dismantled and its functions were split between the departments of state and war (now defense). President Truman soon recognized the inefficiency of this arrangement and created the Central Intelligence Group, which could be considered a smaller precursor to the National Security Council. The following year the National Security Act of 1947 created the Central Intelligence Agency and National Security Council, while formally defining the duties of the director of Central Intelligence. The duties of the DCI had been further defined over the years by tradition, congressional acts, and Executive Orders. The Director of the Central Intelligence Agency (D/CIA) is a statutory office (50 U.S.C. § 3036) that functions as the head of the Central Intelligence Agency, which in turn is a part of the United States Intelligence Community. Beginning February 2017, the D/CIA was elevated to Cabinet of the United States level status, as designated by the president of the United States. This ended with the beginning of the Biden administration. The post of DCI was established by President Harry Truman on January 23, 1946, with Admiral Sidney Souers being the first DCI, followed by General Hoyt Vandenberg who served as DCI from June 1946 to May 1947. The DCI then ran the Central Intelligence Group (CIG), a predecessor of the CIA. The office of DCI thus predates the establishment of the Central Intelligence Agency. The CIA was created by the National Security Act of 1947, which formally defined the duties of the Director of Central Intelligence. This 1947 Act also created the National Security Council. Until April 2005, the DCI was often referred to colloquially as the "CIA Director", even though he was head of both the CIA and the broader Intelligence Community. After the September 11, 2001, terrorist attacks on the United States and the subsequent investigation by the 9/11 Commission, a movement grew to re-organize the Intelligence Community. That movement prompted the passage of the Intelligence Reform and Terrorism Prevention Act in December 2004, which split the DCI's duties among two new offices. The Office of the Director of National Intelligence (DNI) would serve as head of the Intelligence Community and advise the NSC on intelligence matters. The Director of the Central Intelligence Agency would serve as chief administrator of the CIA. The reorganization took effect on April 21, 2005. The 19th and last DCI, Porter J. Goss became the first director of the CIA, while John Negroponte became the first DNI. The Director of Central Intelligence (DCI) was the head of the American Central Intelligence Agency from 1946 to 2005, acting as the principal intelligence advisor to the President of the United States and the United States National Security Council, as well as the coordinator of intelligence activities among and between the various US intelligence agencies (collectively known as the Intelligence Community from 1981 onwards). The office existed from January 1946 to April 21, 2005. After the Intelligence Reform and Terrorism Prevention Act it was replaced by the Director of National Intelligence (DNI) as head of the Intelligence Community and the Director of the Central Intelligence Agency (D/CIA) as head of the CIA.