Carroll Shelby was a formidable driver long before he began building cars, and he had the experience and expertise to extract the most performance from a car. As a race car driver, his greatest success was co-driving the winning 1959 24 Hours of Le Mans entry, one of the pinnacles of motorsport competition. Although he had great success on the track, it was his collaboration with the Ford Motor Company that cemented his legacy.
 

The Ford Mustang, introduced mid-year in 1964, was originally conceived as a sporty car for the masses. It used the exiting Falcon platform and borrowed components already in production, which helped in keeping costs down and getting it to the market quicker. When it was time to bestow the Mustang with Ford's 'Total Performance' campaign, Ford turned to Mr. Shelby to transform it into a proper sports car capable of competing with the Chevrolet Corvette at the track. But first, Ford would have to convince the Sports Car Club of America that the Mustang was not a 2+2 design and thus not a true sports car.

The Sports Car Club of America, the sanctioning body for amateur sports car racing, initially rebuffed Ford, so Ford then turned to Carroll Shelby to rectify the situation. Mustering all of his Texas charm, Shelby coaxed a solution from the SCCA's Executive Director, John Bishop, on what it would take to make the Mustang a production 'sports car.' The result was the purpose-built 1965 Shelby GT350, homologating the Ford Mustang for SCCA racing. The production Ford Mustang GT built at the San Jose plant was sent to the Shelby American facility in Venice, California where they were transformed into (essentially) a racecar for the street. Numerous performance modifications were made along with subtle styling changes to distinguish it from the base Mustang.

Carroll Shelby's GT350 was introduced for 1965 and was immensely successful, winning the 1965 SCCA B-Production championship with Jerry Titus. The Shelby Mustang would dominate the competition from 1965 through 1967, winning three straight SCCA B-Production championships.