The agency was created as the Office of Civil Defense in 1951. In 1984, the OCD name was changed to the Tennessee Emergency Management Agency after the Waverly propane disaster.
In 2002, TEMA changed direction with the appointment of Major General (retired) James H. Bassham who previously commanded the Tennessee Air National Guard as the Assistant Adjutant General for Air. General Bassham was able to quietly turn the agency from a reactive organization into a proactive entity with plans for multiple courses of action.
TEMA was especially busy during 2003 coordinating responses to deadly tornadoes in Jackson, Tennessee and severe straight-line windstorms in Shelby and Fayette counties. In fact, each year has shown its potential for threatening weather with other serious tornado outbreaks occurring in 2006 and 2008. TEMA's coordination of emergency assistance and response continued as flooding and more severe weather resulted in disaster declarations in 75 counties across the state.
By 2004 TEMA had designated more than 30 emergency service coordinators (ESC) from all departments and agencies. In September 2006 the State Emergency Operations Center was reopened after a complete renovation that included computers, telephones, radios, offices, and other integrated systems costing over $4.7 million. Governor Phil Bredesen was present for a TEMA open house where three new communications trailers and a communications and command post bus were displayed to reflect the agency's new capabilities. In July 2006, an independent researcher at the University of North Carolina at Chapel Hill concluded that Tennessee, among three other states, stood out because of their successful emergency management web sites. This study was referenced in an article in the Spring 2007 volume of Emergency Management Magazine. Other articles began to appear in newspapers and magazines about TEMA's conditional accreditation by the Emergency Management Accreditation Program (EMAP) of Lexington, Kentucky and about TEMA's ability to plan, to communicate, and to organize in a disaster. In August 2007, an Associated Press story reported that the Federal Emergency Management Agency had determined that Tennessee was one of only 10 states with plans capable of being executed immediately in a disaster. By December, TEMA had added three fulltime Emergency Services Coordinators from the Department of Safety, Department of Transportation, and Department of Environment and Conservation which dramatically enhanced emergency planning and operations response capabilities. Other planners and representatives were soon after provided by the Department of Health and the Department of Human Services.
On November 16, 2007, TEMA received a crowning achievement with the announcement that the Emergency Management Program of the State of Tennessee had achieved permanent national accreditation (5 year period) by EMAP. A marble plaque of recognition was presented to Governor Phil Bredesen and Director James Bassham in January of 2008. At the time, Tennessee was one of only 12 states that had achieved national accreditation at that time.