The National Security Act of 1947, 5 U.S.C. § 171 et. seq., (the Act) created the Department of Defense (DoD) and gave its officers the authority to control their departments. Though the Act did not explicitly authorize the creation of a clearance program, the DoD implemented one, which was used to evaluate fitness for security clearance through hearings and fact determinations. Greene (plaintiff) was an aeronautical engineer employed by a private manufacturer that produced goods for the armed services. The nature of Greene’s job required security clearance. After proceedings that did not afford him the rights to confrontation and cross-examination, Greene was discharged from his employment solely based on a determination by the DoD program that his clearance should be revoked. Greene argued that the actions taken by the DoD were not authorized by Congress or the president and violated Fifth Amendment Due Process Clause. The federal government (the Government) (defendant) contended that authorization from Congress could be inferred from a number of other contract and criminal statutes that showed Congress’s recognition of the importance of keeping military secrets secure. The Government also argued that congressional authorization was implied from the continued appropriation of funds by Congress to different aspects of the DoD’s clearance program. The lower court ruled in the Government’s favor. Greene petitioned the United States Supreme Court for certiorari, which was granted.