Carroll Shelby in 1958 at the Havana Grand Prix. (HLV/AP)

Carroll Shelby, a failed chicken farmer who roared out of the hills of East Texas to become a champion race car driver and the father of the muscle car, building some of the fastest and sleekest sports cars ever to hit the highway, died May 10 at age 89.

His company, Carroll Shelby International, said he died at a Dallas hospital but did not disclose a cause of death. A Facebook entry under Mr. Shelby’s name in late April said he had been hospitalized with pneumonia.

Among many other achievements in a supercharged life, Mr. Shelby was one of world’s longest-surviving recipients of a heart transplant, having received a new heart in 1990. He was also a principal founder of the International Chili Society, which sanctions thousands of chili cooking contests each year and has raised more than $1 billion for charity.

Mr. Shelby made and lost fortunes, trained pilots during World War II, ran a safari business in Africa and was married at least six times, but he is best known for his daring automotive achievements, first as a driver and later as a designer.

Fresh off his chicken farm, Mr. Shelby won the first race he entered in 1952 and, in short order, became the country’s leading sports-car driver. Once, hurrying to get to a race from his farm, Mr. Shelby didn’t have enough time to change out of his bib overalls. He got more attention for his outfit than for winning the race and, from then on, always wore overalls in the driver’s seat.

He was on the cover of Sports Illustrated in 1957, when he won 19 consecutive races, and twice was named the magazine’s driver of the year. In 1959, he became the second American-born driver to win the 24 Hours of Le Mans endurance race in France (along with his British teammate, Roy Salvadori).

When a heart condition forced him to retire from racing in 1960, Mr. Shelby turned to automotive design. Determined to make the fastest, sexiest sports car on the road, he put a Ford V-8 engine in the chassis of a little-known British roadster, dubbed his new car the Shelby Cobra and created a legend.

As the engine displacement rose from 260 cubic inches to 289 and finally 427, Mr. Shelby almost single-handedly defined the modern muscle car — all horsepower and wide tires, rumbling engines, dual side exhaust pipes and unbelievable speed.

The Cobra was the fastest street-legal car in the land. It could go from zero to 60 mph in four seconds. The speedometer went up to 180.

Although Mr. Shelby manufactured only about 1,000 cars before closing the first edition of his business in 1967, Automobile magazine ranked the original Shelby Cobra as one of the 10 most important sports cars ever built.

“In my opinion,” auto executive Lee Iacocca said in 1995, “Shelby invented the muscle car in this country.”

In a 1995 article in Texas Monthly magazine, journalist Carol Flake described the feeling of being a passenger in a 30-year-old 1965 Shelby Cobra with a 289-cubic-inch engine: “After riding in a Cobra, you may never feel the same way about cars again. It’s a little like riding a runaway thoroughbred after trotting around a ring on a pony. Fear melts into awe.”

In 1964, Iacocca, then an executive at Ford, hired Mr. Shelby to design a sleek, high-performance version of the new Ford Mustang. He came up with the fastback Mustang GT350, which began to steal some of the glamour from the Chevrolet Corvette.

On the racing circuit, Mr. Shelby began to set his sights on the most dominant sports car of the time, the Ferrari.

In the 1950s, Enzo Ferrari, the head of the Italian car company, had made overtures to Mr. Shelby to see if he was interested in driving for his race team. Mr. Shelby, a struggling farmer who earned no prize money in the then-amateur realm of sports-car racing, asked how much Ferrari was willing to pay.

It became clear that Mr. Shelby was expected to drive for the glory of the sport and for the privilege of being at the wheel of a Ferrari. Mr. Shelby turned down the offer and drove an Aston Martin during the 1959 race at Le Mans.

Suffering from dysentery and popping nitroglycerin pills for his heart, Mr. Shelby passed a Ferrari near the end of the race as he sped to the checkered flag.

In 1966, Mr. Shelby was no longer at the wheel, but cars he helped engineer for Ford dominated the Le Mans race and finished in the top three spots.

“Carroll desperately wanted to beat all the Europeans at Le Mans,” C. Van Tune, editor of Motor Trend magazine, told the Dallas Morning News in 2001. “He wanted to show all those fancy, highbred Euros in their slick racing suits that a chicken farmer from Texas could beat them at their own game.”

Carroll Hall Shelby was born Jan. 11, 1923, in Leesburg, Tex., a town of 150 people. He was 7 when his family moved to Dallas.

The young Mr. Shelby liked to ride along with his father, a mail carrier, on his postal route. He was interested in cars, motorcycles and airplanes and, after high school, joined the Army Air Forces. During World War II, he trained bomber pilots at an air base in Texas. During training flights, he dropped love letters from his airplane over his fiancee’s farm.

After the war, he drove a dump truck, worked in the oil business and ran a chicken farm. It was moderately successful for a time, but when 20,000 hens died of disease, “ol’ Shelby was broke,” he later recalled.

He opened a car dealership in Dallas, but mostly he raced cars in the 1950s. In an era when most drivers didn’t wear seat belts and some refused to wear helmets, Mr. Shelby said he attended 29 funerals of fellow drivers.

He had plastic surgery on his face after one crash and had three vertebrae in his neck fused. After shattering his elbow in a road race in 1954, he was back within a few months, with his hand taped to the steering wheel.

Mr. Shelby was, by all accounts, a man of immense charm. He dated a former Miss Universe and said he had been married six times — or maybe seven.

“I don’t count the second one,” he told Vanity Fair in 2006, “ ’cause it happened in Mexico.”

Survivors include three children from his first marriage, to Jeanne Fields; his current wife, Cleo Shelby; a sister; four grandchildren; and six great-grandchildren.

In 1967, Mr. Shelby was one of two organizers of the first International Chili Cookoff in Terlingua, Tex. The event blossomed into the International Chili Society, which stages cooking contests throughout the country for charity. Mr. Shelby marketed his own brand of chili, which he later sold to Kraft Foods.

During much of the 1970s, he lived in Botswana, Angola and the Central African Republic, running a safari business and dealing in diamonds. His other business interests included radio stations, motels and cattle ranches. In 1975, he provided the seed money for the Chili’s restaurant chain, which began in Dallas.

In 1982, Iacocca, then at Chrysler, lured Mr. Shelby back into the car business with the mission of designing a new line of Dodge sports cars, including the Viper.

Mr. Shelby later put updated models of his classic Cobra back in production and, five years ago, returned to Ford to design a new high-performance Ford Mustang GT500.

Even though he had a heart transplant in 1990 and a kidney transplant in 1996, Mr. Shelby never lost his love for speed. At 84, he took the new Mustang out for a test drive, easing the throttle open until he topped out at 150 mph.