There are many things written about James McDonnell, president of the newly formed Mc Donnell - Douglas Corporation. One of his more infamous stories was the chapter when Douglas lost some early orders to Lockheed.
Douglas was just a step away of becoming a monopolist in the 350-seater market. They had a large costumer base with the DC-8 and DC-9 jets while Lockheed was not very successful with its Electra turboprop. The last successful airliner was the Lockheed Constellation which was sold in large numbers in the 1950s. If Douglas would have won the large majority of the early orders, Lockheed would have cancelled the TriStar.
Entry Mr. Mac - James McDonnell was a successful aviation pioneer and businessman. His Mc Donnell company, based in St. Louis, brought out some famous designs, including the F-4 "Phantom". In 1967, the company became the saviour of the famous Douglas Aircraft Company, by merging into the Mc Donnell - Douglas corporation. Unfortunately, together with the needed funds came the mentality of selling military aircraft into the sales department of Douglas... Many books give the main fault to James McDonnell
Namely Delta Air Lines, Eastern Air Lines, TWA and United Airlines were interested in an aircraft of this size in early 1968. Among them, only TWA was favoring Lockheed - in spite of being an early DC-9 costumer. United and Eastern preferred the DC-10, although Eastern was looking for an aircraft slightly larger then the DC-10-10 and similar to the DC-10B. Delta liked both aircraft and was mainly looking at the price. But Douglas failed to present an appropriate financing plan for the aircraft as well as a slightly larger model as a consequense of the "take it or leave it" mentality inherited from McDonnell. The chance to become a monopolist on the 350-seater market was gone.