The 78th Training Division (Operations) ("Lightning") is a unit of the United States Army which served in World War I and World War II as the 78th Infantry Division, and currently trains and evaluates units of the United States Army Reserve for deployment.
One of five exercise divisions in the United States Army, the 78th Division Headquarters, and its 1st Brigade, were for many years headquartered at the Kilmer Reserve Center (the former Camp Kilmer) in Edison, New Jersey with subordinate units located in New Jersey, Rhode Island, Massachusetts, Virginia, Maryland, Pennsylvania and New York.
As a result of the 2005 BRAC, the division's headquarters and its 1st Brigade were relocated to Fort Dix, New Jersey, joining the already located Division's 2d Brigade (LANES) and some 1st Brigade (BCST) subordinate elements.
In late 1999, the division was redesignated from 78th Division (Exercise) to 78th Division (Training Support) to reflect the growing change in the type of training provided by the division's units. There was also an associated change in the manning of the unit, adding National Guard personnel to the regulars and Army Reservists already assigned. This was one of the first instances of the growing multi-component organization of US Army units that deal with Reserve Component training and operations.
In 1999, the 189th Infantry Brigade was reflagged as the 4th Brigade, 78th Division (TS) and merged with the existing 4th Brigade, 78th Division (Exercise). The reorganization created a unique unit consisting of active-component, National Guard, civilian and drilling US Army reservists.
The 4th Brigade is a tenant unit on Fort Bragg with headquarters at the 78th Division (Training Support), Edison, New Jersey. The brigade's responsibility is to train, coach, teach and mentor the Reserve and Army National Guard units of North Carolina.