A "joint board" bringing together top leaders of the U.S. military was established in 1903 during President Theodore Roosevelt's administration. It gained members after World War I but remained largely advisory. The joint board was eclipsed during World War II by a "unified high command" that became known as the Joint Chiefs of Staff. The National Security Act of 1947 formally established its official role in military matters.
Five notable chairmen of the Joint Chiefs of Staff:
GEN. OMAR N. BRADLEY
A World War II hero with the rare distinction of reaching five-star rank, he was the first chairman of the Joint Chiefs. He served from August 1949 to August 1953, a period marked by the outbreak of the Korean War and, before that, a "revolt of the admirals" in a Washington battle over nuclear war roles between the Navy on one side and the Army and Air Force on the other.
GEN. EARLE G. WHEELER
He held the chairman job longer than anyone else, from July 1964 to July 1970, after serving two years as Army chief. A combat veteran of World War II, his tenure leading the Joint Chiefs was dominated by the Vietnam War. According to an official history of the Joint Chiefs, his influence with the White House was overshadowed by Defense Secretary Robert McNamara.
GEN. COLIN POWELL
The first black officer to serve as Joint Chiefs chairman, Powell held the job from Oct. 1, 1989, in the waning days of the Cold War, to Sept. 30, 1993. He is probably the best-known among former chairmen. He later helped negotiate a peaceful transfer of power in Haiti in September 1994 and served as secretary of state from 2001 to 2005, making him one of the few former chairmen to become a diplomat.
GEN. HENRY 'HUGH' SHELTON
He was aboard a military plane en route to Europe when a hijacked airliner slammed into the Pentagon on Sept. 11, 2001. He had been appointed by President Bill Clinton and served from Oct. 1, 1997, to Sept. 30, 2001. He wrote in a memoir that the second secretary of defense he served with, Donald H. Rumsfeld, tried to diminish the authority of the chairman.
ADM. MICHAEL MULLEN
A former head of the Navy, Mullen became one of the most outspoken Joint Chiefs chairmen during his term from Oct. 1, 2007, to Sept. 30, 2011. He is remembered for his blunt public call for ending the legal limits on gay men and lesbians serving in uniform, and for acknowledging in December 2007 that the urgency of avoiding defeat in Iraq had made Afghanistan a second-priority war.
Joint Chiefs of Staff: http://www.jcs.mil