They went by several nicknames — Gooneybirds, Skytrains, Dakotas. Reliable and virtually indestructible, in 1940 they accounted for 87 percent of the commercial aircraft flying in the United States.

The DC-3 and its military sibling, the C-47, were stubby, propeller-driven planes that got the commercial air-cargo industry off the ground. No one has tallied how much freight — commercial and military — moved in their bellies or the fat fuselages of the freighter versions, but the number was immense. More than 11,000 DC-3s and C-47s were built before Douglas Aircraft ceased their production in 1946, sending the last one off the line to Sabena Airlines in Belgium.

Although no plane in aviation’s pre-jet era had any comparable impact, the DC-3 was only one of several cargo planes to emerge during the first half of the 20th century.

Twenty-two years after the Wright brothers went airborne at Kitty Hawk and 98 years after The Journal of Commerce began publication, pioneer planemaker Donald Douglas rolled out the first all-cargo aircraft in Santa Monica, Calif. The C-1, a singleengine biplane introduced in 1925, could haul 2,500 pounds of freight up to 750 miles at 75 miles per hour. That same year, Douglas’ rival, William Boeing, introduced his Model 40 “mailplane,” with a capacity of 1,000 pounds and a top speed of 135 mph. The problem in those days was finding civilian shippers brave enough to put their cargo aboard the planes. Douglas found an early customer in the Army Air Corps, Boeing in the post office.

Boeing wanted to be more than just a vendor. When Congress ordered the U.S. Post Office Department to sell its airmail routes to private airlines in 1926, he bid for the San Francisco-to-Chicago route, offering to move the mail for $2.89 a pound, half of what the post office was paying. Boeing won the bid the following year and unveiled a new mailplane, the Model 40A, equipped with a more 420-horsepower engine, a 20 percent bigger payload and a two-seat passenger cabin located behind the pilot’s open cockpit and the mail compartment.

Boeing built 25 Model 40As in 1927 and formed his own airline, Boeing Air Transport Co., to haul mail and passengers. He headquartered it in Chicago 2,000 miles from his Seattle aircraft plant. Ironically, Boeing headquarters now is back in Chicago.

Automobile tycoon Henry Ford, fascinated by new contraptions, briefly midwifed the infant air-cargo industry. He quietly financed the brainchild of William B. Stout, an inventor who built a metal-framed airplane, a radical idea in the mid-1920s. But the visionary Ford saw several new revenue streams. He formed what arguably was the first all-cargo airline, Ford Air Transport Service, to ship Ford spare auto parts between Ford plants on Ford Trimotor aircraft otherwise known as the Tin Goose.

Flush with success and a perfect safety record, Ford’s new airline snared U.S. mail contracts between Detroit and Cleveland and Chicago. The automaker bailed out of the airline business in 1928 and sold its routes to Stout, who had launched his own mail and passenger airlines. Ford’s Trimotors were selling briskly.

By the 1930s, William Boeing was no longer a participant in the dogfight for commercial aircraft supremacy. The battle shifted to Southern California where the twinengine Douglas DC-2 and the Lockheed C-35 were wooing Air Corps contracts as cargo and troop transports. To win “flyoff ” competitions, Donald Douglas installed a larger cargo door in his DC-2 and added a bigger tail.

That, combined with Douglas’ single-minded salesmanship and his continual design and mechanical improvements, produced the DC-3 and the C-47, which became the flagships and workhorses of the aircargo industry.

Fast forward to 2002. The “grand old lady” is still slogging through the skies. On her 60th birthday in 1995, historians estimated that nearly 1000 DC-3/C-47s were still flying, including 300 as military aircraft, although some say the number is inflated.

The freighter versions are still making money for their owners. Miami Valley Aviation in Middletown, Ohio, has the biggest fleet of DC-3 and C-47 all-cargo aircraft operating today. They work in the “on-demand” airfreight market, hauling mainly auto parts for General Motors, Ford Motor Co., DaimlerChrysler and Honda.

Miami Valley has Lears and Falcons for shippers needing faster transport for high-value cargos but if it’s big and bulky and speed isn’t a priority, freight forwarders call Miami Valley and the eight or nine other on-demand cargo aircraft operators that own one or two DC-3s.

Miami Valley Aviation’s chief pilot, Kevin Uppstrom, has been flying the company’s DC-3s for 20 years. Asked what it’s like to fly a Gooneybird in the jet age, he sums up the thrill in a word — “slow.” Although he’s signed autographs for wide-eyed youngsters and aviation buffs at takeoffs and landings, Uppstrom says the freighters fly at night and usually land at cargo buildings far from passenger terminals. It’s just a job.

But the DC-3 is still in the mainstream. The aircraft’s 6,400- pound payload can move eight pallets or “little and big pieces, or bins and racks or anything,” Uppstrom said. Miami Valley used to have contracts with the giants of the airfreight industry — Fed Ex, UPS, Emery/Menlo, Airborne Air Freight. No longer. “Today we do a little bit of work for all of ’em,” Uppstrom said. There’s no much glamour anymore in operating the DC-3. It’s pretty low-tech, the pilot said. “Customer calls up and says, ‘I got freight here. I want to send it there. How much does it cost? How long will it take?’ ” The price is always the same: $3.75 per statute mile round-trip.