The Douglas DC-6 was one of the first airplanes to fly a regularly scheduled around-the-world route. With its higher performance, increased accommodation, greater payload and pressurized cabin, it was a natural evolution of the DC-4.

Although the DC-6 had the same wingspan as the DC-4, its engines helped it fly 90 mph (145 kph) faster than the DC-4, carry 3,000 pounds (1350 kilograms) more payload and fly 850 miles (1368 kilometers) farther. The DC-6 could maintain the cabin pressure of 5,000 feet (1524 kilometers) while flying at 20,000 feet (6096 meters).

American Airlines and United Airlines ordered the commercial DC-6 in 1946, and Pan American Airways used the DC-6 to start tourist-class service across the North Atlantic. The 29th DC-6 was ordered by the U.S. Air Force, adapted as the presidential aircraft and designated the VC-118. It was delivered on July 1, 1947, and named The Independence after President Harry Truman’s hometown, Independence, Mo.

The larger, all-cargo DC-6A first flew Sept. 29, 1949; the larger capacity DC-6B, which could seat up 102 people, first flew Feb. 10, 1951. After the Korean War broke out in 1951, the military ordered DC-6As modified as either C-118A Liftmaster personnel carriers, as the Navy’s R6D transports or as MC-118As for aeromedical evacuation. Between 1947 and 1959, Douglas built a total of 704 DC-6s, 167 of them military versions.

By the end of the twentieth century, DC-6 airplanes were still flying around the world.