His motorsport career began as a road racing driver, he made his Grand Prix debut at 41 and he died aged 46, several days after crashing during testing for the 1966 24 Hours of Le Mans.

In addition to Formula One, Walt Hansgen was a dominant road racer from the early 1950s and 1960s, winning numerous races at VIR, the famed course at Bridgehampton, and Watkins Glen through to his death at Le Mans in France in 1966.

Hansgen won the Formula Junior race at the inaugural United States Grand Prix meeting at Sebring, Florida, on December 12, 1959, driving a Stanguellini.

Hansgen was killed when he crashed a 7-liter Holman & Moody Ford GT 40 Mk2 sports car while driving in the rain during the Le Mans tests on April 3, 1966.

"[4] Ford crew members later said that Hansgen had continued to push hard in the damp weather, although he had been warned by team manager Carroll Smith to take it easy.