After years of success in amateur sports-car racing, Donohue s professional career took off in 1966 when he drove a factory Ford GT40 at Le Mans and a Lola T70 for Penske in the Can-Am Challenge. He arrived on the public stage at a time when American racing was attracting a wider audience through exciting new series such as the Can-Am and the Trans-Am Sedan Championship, which he would soon dominate, driving Chevrolet Camaros and AMC Javelins. Donohue s greatest triumphs would come in the early 1970s: In 1972 he won the Indy 500, and a year later he captured the Can-Am title in the overpowering Porsche 917-30. After a brief retirement he returned to racing in Formula One, only to die following an accident during practice for the Austrian Grand Prix in 1975.