Reactivated on 8 September 1955 by Air Defense Command (ADC) at Truax Field, Wisconsin under Eastern Air Defense Force. Was responsible for the construction and development of several Semi Automatic Ground Environment (SAGE) Data Centers. SAGE centers developed were at Truax Field, Wisconsin (DC-07) and Combat Center (CC-02); Direction Center (DC-10) at Duluth Municipal Airport, Minnesota; and Direction Center (DC-14) at K.I. Sawyer Air Force Base, Michigan. Its defense area included parts of Wisconsin, Michigan, Minnesota, Illinois, Indiana, Missouri, Iowa and southern parts of Ontario, Canada as part of the Pinetree Line.