On 25 April 1947 then chief of staff of the United States Army, Dwight D. Eisenhower, signed general Orders 91 creating the ROTC on the University of Illinois Urbana Campus. Because the old Navy Pier campus was an extension of the University of Illinois, the ROTC detachment at Navy Pier was officially part of the University of Illinois program. ROTC flourished during the post WWII years. The Fire Battalion’s history indicates a cadet battalion enrollment reaching 600 cadets during the early 1950s.
In 1965 the university campus moved from Navy Pier to its present location, offering courses in four colleges to about 5,000 students. During the Vietnam War years from 1965-1975 the Fire Battalion was still a detachment of the University of Illinois at Urbana-Champaign. In 1973, pursuant to Department of the Army Guidance, women were allowed into the ROTC program. Around 1976 the University of Illinois at Chicago Fire Battalion was officially designated as a battalion separate and distinct from the University of Illinois at Urbana-Champaign. In 1978 a staff study, nicknamed the subway study, was conducted by the Loyola Instructor Group at the behest of the Second Region commander. The study was designed to test the feasibility of tying all of the Chicago-area programs together using the subway-rapid transit system. The idea was abandoned due to excessive travel times for students.
Under President Ronald Reagan, during the Cold War years of the1980s, the program was reinvigorated, and many of the city's smaller schools and universities were cross-enrolling in the UIC ROTC program. On 17 May 1991 the Loyola-DePaul Battalion commissioned its last five cadets and folded its colors for the last time. The Fire Battalion assumed responsibility for the cross-enrolled students from Loyola and DePaul universities (now Rambler Battalion) as well as from Northeastern Illinois University and Northwestern University. The latter two schools were official extensions of the Loyola Battalion. In 1996 the Fire Battalion became the host ROTC unit for all of the Chicago area. Chicago State University folded its colors as did Illinois Institute of Technology. With the closing of these last two Chicago-area detachments, the Fire Battalion now was the only battalion in Chicago.