In 1976, the United States Congress passed the National Emergencies Act (NEA), Pub. L. 94–412, 90 Stat. 1255. It was enacted September 14, 1976 but did not take effect until two years later in 1978. You can find it in the United States Code at 50 U.S.C. § 1601–1651. A compiled Legislative History can be found in the U.S. Legislative History file located in Hein Online. If you are not a student, staff or faculty member at the University of Hawaiʻi at Mānoa, you can visit the Law Library at 2525 Dole Street to access this material.
Prior to passing the NEA, Presidents had authority to declare a national emergency if expressed in specific statutes or implied by the United States Constitution. The first use of this power can be traced back to 1775 when the Continental Congress authorized President Hancock to use force in stomping down Shay’s Rebellion, an insurrection movement in Massachusetts where farmers committed violent acts on U.S. courthouses and other government properties as a form of protest against burdensome economic policies. (The rebellion is named after Daniel Shays, a farmer and solider who fought at Bunker Hill and was a leader of this rebellion.) The first “emergency proclamation” issued as such was made by Woodrow Wilson on February 5, 1917 (39 Stat. 1814) and concerned water transportation. President Wilson invoked the authority expressly authorized to him in the legislation establishing the United States Shipping Board (39 Stat. 728).
Prior to the NEA, there was no procedure involving Congress or requirement for notification when national emergencies were proclaimed or terminated. Concern over emergency proclamations escalated during the Vietnam War and the U.S. incursion into Cambodia. By declaring a national emergency, a President could bypass the provisions of the Constitution in declaring war, a responsibility clearly left to the U.S. Congress and not the Executive branch of government. These types of maneuvers led Congress to pass legislation that laid out procedure for both enacting an emergency and terminating one.
The NEA does not provide any specific emergency authority on its own. When a President declares a national emergency under the NEA, the declaration activates the emergency provisions of other federal statutes. For example, if there is a health pandemic, there is nothing in the NEA that provides for quarantine of infected individual, but there are emergency provisions contained in other parts of the United States Code and the Code of Federal Regulations. Under the NEA, the Presidential declaration must identify what authorities s/he is specifically enacting, and the U.S. Congress must be notified immediately. The most current proclamation made by President Trump invokes the emergency military construction authority in 10 U.S.C. 2808.
An emergency declaration takes the form of an Executive Order and is published a few days after it is announced in the Federal Register (click here for older orders dating back to 1994). Executive Orders live permanently in Title 3 of the Code of Federal Regulations (click here for older issues dating back to 1992). The Brennan Center as compiled a list of the Executive Orders declaring a national emergency since the NEA was passed: https://apps.npr.org/documents/document.html?id=5740420-Declared-National-Emergencies As of the writing of this post, the declaration had not been assigned an Executive Order Number, nor was it published in the Federal Register.
In 50 U.S.C. 1622, Congress laid out the provisions for terminating a national emergency. First, Congress can pass a joint resolution at any time to terminate the declaration. In any case, Congress must review the necessity of emergency status every six months. Second, the President can terminate an emergency by proclamation. Third, if the President does not follow through with his/her reporting requirements under 50 U.S.C. 1641, the emergency will automatically terminate 90 days following the failure to provide a 6-month progress report.
To learn more about how Presidential emergency powers developed, you can read the Committee Print, A Brief History of the Emergency Powers in the United States published in July 1974. We also subscribe to a 2014 e-book by Justin P. DePlato titled The Cavalier Presidency: Executive Power and Prerogative in Times of Crisis.