The shape of the modern American military was cast 61 years ago today, when President Harry Truman signed the National Security Act. The Department of War was renamed the Department of Defense, and the secretaries of the Army and Navy were moved from the president’s cabinet and placed under the secretary of defense. The same act created the U.S. Air Force, the joint chiefs of staff, the CIA and the National Security Council. Known simply as “DOD,” the Defense Department is one of the largest organizations in the world, with some 639,000 civilian employees. In addition, there are nearly 1.4 million military personnel on active duty in the Army, Navy, Marine Corps and Air Force.