For the history of the original DC-9, see the post “The Douglas DC-9 Story” on 2023-03-12.
After the merger between Douglas Aircraft and McDonnell Aircraft in 1967, forming McDonnell Douglas, the combined company continued to develop derivatives of the DC-9 for an evolving market, launching the MD-80 in 1980, followed by the MD-82, MD-83, MD-87, and MD-88, with various passenger capacities and, over the years, improved wing design, engines, and cockpit instrumentation. In 1995, the MD-90 entered service, followed by the MD-95, designed to replace aging DC-9s. After the merger of Boeing and McDonnell Douglas in 1997, the MD-95 was renamed the Boeing 717-200. The type remained in production until 2006, bringing the DC-9 saga to an end, after a total of 2441 aircraft of all models and generations had been produced.