In the mid-1930's American Airlines ordered from the Douglas company an advanced version of the DC-2 passenger plane which was operated extensively by them on domestic air routes. In developing the new aircraft, the successful innovative ideas in the layout of the DC-2 were considered, but its construction embraced a variety of further changes, and as a result appeared the DC-3, a plane which defined an epoch in the history of aviation. Its design was so successful and well regarded, that it continued to be operated for passenger transport for many decades.
After the U.S. entry into World War II, it was clear that the army did not have enough transport aircraft. Considerable numbers of the civil DC-3 were requisitioned for army needs, and the Douglas company soon produced the modified C-47, dedicated to the requirements of the military, which differed in having a large cargo door on the side of the fuselage, and a reinforced floor to enable the carrying of heavy military cargo.
The C-47 soon became the most widely used transport aircraft of the nations allied against Hitler. Under Lend-Lease agreements the USA transferred to Great Britain and the USSR a large number of machines of this type, besides which, the USSR established their own production under license.
In the U.S. Air Force the C-47 was used in every theater, but the most famous pages of its military service told of the opening day of the Second Front in France, when a huge air armada crossed the Channel and dropped a great force of paratroopers from the air. In this role, the passenger plane in its new guise as the military C-47, proved to be the best all around aircraft for transportation tasks. It was rather capacious and comfortable for a military vehicle, along with impressive speed and range. No wonder that, after the end of World War II, these machines remained in the ranks of the air arms of the USA, Great Britain, the USSR and France for some time.
Many machines were sold before the war to customers in various countries around the world; and at the end of the war a large number of C-47's found new owners in countries on almost every continent - overall this aircraft was employed in 98 countries which is an absolute record for transport vehicles of the time. The C-47 along with the classic DC-3 is used even today in some countries of Africa and Asia.