Republic Airlines began in 1979 with the merger of North Central Airlines and Southern Airways, the first under airline deregulation. The new airline's headquarters were at Minneapolis-Saint Paul International Airport, though their largest hub was at Detroit Metropolitan Wayne County Airport. Following their buyout of Hughes Airwest in 1980, Republic became the largest airline in the U.S. by number of airports served. They operated the world's largest Douglas DC-9 fleet, with DC-9-10, DC-9-30 and DC-9-50s and also flew Boeing 727-200, Boeing 757-200 and McDonnell Douglas MD-80 jets. In addition, Republic operated Convair 580 turboprops previously flown by North Central. After the merger, losses mounted and service reductions followed. Saddled with debt from two acquisitions and new aircraft, the airline struggled in the early 1980s, and even introduced a human mascot version of Herman the Duck. They reduced service to Phoenix, a former hub of Hughes Airwest, citing their inability to compete with non-union airlines there and eventually dismantled the former extensive route system operated by Hughes Airwest in the western U.S.

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