When Lockheed developed the L1049 Super Constellation, TWA enjoyed an advantage over other airlines, since the plane had non-stop transcontinental range, and was faster than the DC-6 (TWA marketing people didn't think people would sit still for a non-stop trip, however, and insisted on a stop until American announced upcoming non-stop service with their new DC-7's!). To counter this threat from the Super Conny, American requested that Douglas develop a plane with the L1049's engines (Wright R-3350's). Douglas was doubtful that a plane like that would sell, so American ordered 25 for $40 million, to provide an incentive. American ended up owning 34 DC-7's, and sales were made exclusively to domestic US operators which used them on transcontinental routes, since the DC-7 didn't have the range for trans-ocean non-stops and thus would not be much improvement over the DC-6B. However, they were very successful in transcontinental service, since they were faster than the Super Constellations, and allowed American to advertise 8 hour non-stop service.

Sales eventually totalled 105, with the owners being United (57), American (34), Delta (10), and National (4). However, Douglas went on to modify the DC-7 (with more fuel) to the DC-7B, and (with a lengthened fuselage and wings) to the DC-7C Seven Seas, and eventually sold a total of 338 of the DC-7 series, at a substantial profit. The DC-7's proved to be less reliable than the fabled DC-6B, and less economical as well. Thus, the DC-7's had a short stay in service with the major airlines, and were sold soon after the arrival of the jets. They worked for many years for 2nd tier airlines and as freighters or fire bombers, but most have been scrapped - suffering in comparison to arguably the best propliner ever, the DC-6B.