IEMA began as the Illinois Civil Defense Agency (ICDA), created by the General Assembly in 1951 to protect the public in the event of a nuclear attack. Other duties of the ICDA included conducting training and public information programs, surveying available resources, making contingency plans, establishing mobile support teams and providing needed supplies and equipment following a nuclear attack.

The Illinois Civil Defense Agency was replaced in 1975 by the Illinois Emergency Services and Disaster Agency (ESDA). Responsibilities of this newly named agency were expanded to include fires, floods, earthquakes, and other natural or manmade disasters in addition to nuclear disasters.

The Illinois Department of Nuclear Safety (IDNS) was created in 1980 as the first cabinet level state nuclear regulatory agency in the United States following the occurrence at Three Mile Island, Pennsylvania, on March 28, 1979. During the Three Mile Island event, equipment malfunctions, design related problems and worker error led to a partial meltdown of a reactor core causing very small off-site releases of radioactivity. The principal goals of DNS were to study safety questions and to ensure that the citizens of Illinois would be safe from nuclear power.

Effective Jan. 1, 1992, ESDA became the Illinois Emergency Management Agency (IEMA). In 2003, Executive Order 12 transferred functions of the Department of Nuclear Safety (DNS) to IEMA. The consolidation was carried out to share the resources of these two unique organizations while preserving public safety services and centralizing coordination and communication among various entities at the state level.

For more information: A Brief History of the Illinois Emergency Management Agency