Its cabin was  wide, and a version with 21 seats instead of the 14–16 sleeping berths of the DST was given the designation DC-3. There was no prototype DC-3; the first DC-3 built followed seven DSTs off the production line and was delivered to American Airlines. American Airlines inaugurated passenger service on June 26, 1936, with simultaneous flights from Newark, New Jersey, and Chicago, Illinois.
The cabin was spacious, and a variant with 21 seats instead of the 14–16 sleeping berths of the DST was designated DC-3. There were no prototypes for the DC-3; the first DC-3 built followed seven DSTs off the production line and was delivered to American Airlines. American Airlines launched passenger service on June 26, 1936, with simultaneous flights from Newark, New Jersey, and Chicago, Illinois.