Who thought of the idea of Le Mans 24 Hour racing?

The 24 Hours of Le Mans (24 Heures du Mans) is a sports car endurance race held annually since 1923 near the town of Le Mans, Sarthe, France. Commonly known as the Grand Prix of Endurance, it is organised by the Automobile Club de l'Ouest (ACO) and runs on a circuit containing closed public roads that are meant not only to test a car and driver's ability to be quick, but also to last over a 24-hour period.

* http://en.wikipedia.org/wiki/24_Hours_of_Le_Mans