This was the debut race of the future world champion Mario Andretti, and his first Formula One pole position.

Stewart was unable to defend his provisional pole during the second practice day due to a broken stub-axle.

On race day, a huge crowd of 93,000 anticipated a strong home showing with two other Americans also on the grid—Dan Gurney, in seventh, and Bobby Unser, in nineteenth.

After the first lap the order was: Stewart, Andretti, Amon, Hill, Jochen Rindt, Denny Hulme, Gurney, John Surtees and Bruce McLaren.

However, he continued without losing his position until lap 13, when his pit crew taped the car back together, and dropped to thirteenth place.

On lap 97, a minute and twenty seconds ahead of Bruce McLaren, Jo Siffert's Lotus began to sputter, and he signaled to his pit that he would stop to refuel in the next round.

Stewart led every lap in his Matra-Ford and was threatened only once, when he rounded a corner to find two spectators walking across the track.

It was his first American Grand Prix victory and kept alive hopes for his first World Drivers' Championship with just one more race to go.