Midwest Airlines actually began life in 1948, when Kimberly-Clark began providing air transportation for company executives and engineers between the company's Appleton headquarters and their owned mills.
In 1969, K-C Aviation was born out of this. K-C was dedicated to the maintenance of corporate aircraft. After the Airline Deregulation Act of 1978, Kimberly-Clark and K-C Aviation decided to form a regular scheduled passenger airline, and out of that initiative, Midwest Express was born in 1984.
In 1985, Midwest Express saw the darkness of tragedy happen to them for the first (and so far only) time in the airline's history, when a DC-9 of the airline crashed while taking off from Milwaukee, bound for Atlanta's Hartsfield International Airport. According to FAA reports, the crash was caused by failure of the plane's right engine, caused by engine fatigue. The engine's failure, in turn, caused the plane to stall during the take off procedure, causing the crash and the deaths of the 31 people on board.
Midwest Express operates an exclusive fleet of DC-9 jet aircraft, while its commuter partners operate smaller plane types.