Name the corporation that built the Lunar Rover, helped start Greyhound and DirecTV and, for its "day job," has been the world's largest automaker for the last 77 years. OK, the headline gave it away; it's General Motors, GM to most of us. The Michigan behemoth, which has struggled recently and may lose its largest automaker title this year, marked a century in business last month, a time in which GM has seen mostly success.

GM's history could fill volumes. After all, we're talking about Chevrolet, Cadillac, Buick, Pontiac and GMC - names woven into the fabric of our songs, movies and culture. And that doesn't count Saturn, Hummer and Saab or Opel, Holden and Vauxhall, GM's overseas brands. And among GM's many defunct nameplates, Oldsmobile (1897-1904) deserves special mention.

GM's many industry innovations must also be considered, including the first electric starter, ethyl gasoline, modern auto design, the first concept car (Buick's 1938 Y-Job), the first airbag in a production car, the catalytic converter (technology GM shared with the industry), the safety/security/information service OnStar, the concrete highway median safety barrier, independent front-wheel suspension, unibody construction and the first full-size hybrid pickups.

Today, GM employs more than 250,000 people and makes cars and trucks - 9.37 million in 2007 - in more than 30 countries. And though GM lost $38 billion last year, it's still the world's ninth-largest publicly traded company by revenue.

The beginning

Not surprisingly, GM's start was more modest - though very frenetic. Christened on Sept. 16, 1908, GM was a holding company run by William Durant with one nameplate: Buick. That changed, however, as GM quickly acquired Oldsmobile, Oakland, Cadillac, AC Sparkplug, the truckmakers that became GMC (Rapid, Reliance, Randolph) and several other companies. In fact, because of GM's many acquisitions, pieces of its history actually predate the main company. (Oldsmobile was born in 1897, Opel in 1899, Cadillac in 1902, Buick in 1903 and Oakland, later Pontiac, in 1907.)

GM's best-selling brand, Chevrolet, probably owes its existence to all this activity. With GM saddled by debt and slow sales, bankers ousted Durant in 1910. He then formed Chevrolet with racer Louis Chevrolet and his brother Gaston, and secretly bought GM stock until he was back in control in 1916. Chevy then joined the GM fold but Durant was gone by 1920, replaced by Alfred Sloane, who led GM to the top of the carmaking industry.

Number one

GM arrived in Europe in the 1920s, buying England's Vauxhall (1925) and Germany's Opel (1929). GM also launched Pontiac (1926) and claims that the 1927 La Salle - designed by the legendary Harley Earl, largely responsible for the first auto design department, the first concept car and the 1950s' fins and chrome - marked the beginning of true automotive design.

The 1920s also marked the changing of the guard when GM passed Ford as the world's biggest automaker. By meeting consumers' desire for style, power and convenience, and offering credit (which Henry Ford opposed on moral grounds), GM vaulted to number one and never looked back.

The rest of the story

Sales reached 25 million vehicles before World War II, when GM converted 100 percent of its production to the American war effort, producing $12 billion worth of planes, truck, tanks and engines. Post-war brought V-8s, the Cadillac Coupe de Ville, and the Chevy Corvette and Bel Air. The late '50s saw the first Pontiac Bonneville and Cadillac's Eldorado. GM was America's largest company and the largest private employer on the planet.

With the help of the Chevy II, Pontiac Firebird and Chevy Camaro, GM sales passed 100 million U.S.-made vehicles in 1967. But emissions regulations and oil crises led to vehicle downsizing in the 1970s. And GM's market share, already dropping because of stiff competition from imports, suffered when vehicles like Corvair, Vega and Citation had quality problems.

GM had also started "competing with itself" in the late 1950s. The company's original "step" lineup - entry-level Chevys, then Pontiacs and Oldsmobiles leading to higher-priced Buicks and Cadillacs - changed when brands added models in competing price ranges. Competition ultimately forced GM to eliminate each brand's unique engines and share more parts and platforms across brands.

Cost-cutting, better quality vehicles and the popularity of high-margin pickups and SUVs like the Chevy Suburban righted GM's ship in the 1990s. Before 9/11, with its stock price high and Buick returning to China, GM seemed poised to hold onto its resurgence, but a recession and pension-fund problems hurt the corporation. Add the 2004 decision to spend less on new car models and more on new light trucks, which arrived when fuel prices began spiking, and we've reached today's current challenges. Of course, more subjects could be highlighted, such as GM's racing (Impalas currently run in NASCAR); Mr. Goodwrench; AC Delco; legendary badges such as Corvette, Cutlass, DeVille, Grand Prix and Century; diesel locomotives, buses and numerous other topics and models.

GM today

Cadillac has changed its image with edgier styling and new names, and Buick revamped its entire lineup recently. And, in addition to moving to more fuel-efficient vehicles, GM currently has a number of green initiatives, including its current hybrid models (Saturn Vue and Aura Green Lines, Chevy Malibu and Tahoe, GMC Yukon). GM also will soon introduce the Chevy Volt, which can run on electric batteries, gas, E85 and biodiesel.