The ACO’s origins lie with the Automobile Club de la Sarthe, established in the town of Le Mans. In 1906, this group included Amédée Bollée and Paul Jamin, a winner of the 1897 Paris-Dieppe race in a Léon Bollée tricar. With the help of the larger Automobile Club de France, they organized a race on local public roads, a 65-mile triangular course connecting Le Mans with Saint-Calais and La Ferté-Bernard. The 12-lap race, titled the Grand Prix de l'ACF, was held over two days and won by Ferenc Szisz driving a Renault; this race would eventually become the French Grand Prix.
After World War I, the ACO focused on designing a shorter circuit on public roads south of the city. The organization’s chief secretary, Georges Durand, magazine editor Charles Faroux of La Vie Automobile, and tyre manufacturer Emile Coquille conceived of a 24-hour race. The inaugural 24 Hours of Le Mans took place on 26 May 1923, with the first entry lodged with the ACO by John Duff driving a Bentley.
The Le Mans circuit was occupied by the Royal Air Force in 1940, and subsequently by the Germans at the end of that year. Le Mans was liberated in August 1944, but the 24 Hours race would not resume for almost five years. Following the war, the ACO grounds and circuit were in ruins, damaged by Allied and German forces. Reconstruction began with aid from Government Minister and Sarthe députée Christian Pineau, who provided initial funding, and an ACO-launched loan. In 1946, the British Racing Drivers' Club established a “Le Mans Fund” for the ACO, raising £358 and 11 shillings to assist with facility rehabilitation. Rebuilding of the circuit started on February 7, 1949, and the first post-war event was held on 25–26 June of that year, with Pineau and Faroux giving the starting signal. Two new spectator stands were named in honor of racing drivers and resistance fighters Robert Benoist and Jean-Pierre Wimille.
During the ACO's 24 Hours of Le Mans event in 1955, an accident resulted in 84 fatalities, the worst in motorsport history. This led to changes by the ACO to the circuit’s buildings and procedures, as well as redesigns of the pit lane and front stretch where the accident occurred. It also prompted revisions to ACO rules regarding the types of cars permitted in the 24 Hours of Le Mans, including the application of a fuel-consumption formula.
The ACO serves as a ruling body for race series, particularly sportscar racing. Currently, the ACO runs the 24 Hours of Le Mans, 24 Hours of Le Mans Moto, Le Mans Classic, French motorcycle Grand Prix, FIA World Endurance Championship, Asian Le Mans Series, European Le Mans Series, Le Mans Cup, and Prototype Cup Europe. Past series include the 1000 km of Le Mans, American Le Mans Series, Intercontinental Le Mans Cup, Formula Le Mans, Le Mans Autumn Cup, World Sportscar Championship, FRD LMP3 Series, and UK LMP3 Cup Championship. The 1967 French Grand Prix, a Formula One race, was held on the Bugatti Circuit, Le Mans, on July 2, 1967, and was described by Motor Sport as "The Grand Prix of the Car Parks."
The presidents of the ACO have included Adolphe Singher (1906–1910), Gustave Singher (1910–1947), Paul Jamin (1947–1951), Jean-Marie Lelièvre (1951–1973), Raymond Gouloumès (1973–1992), Michel Cosson (1992–2003), Jean-Claude Plassart (2003–2012), and Pierre Fillon (2012–).
This article is based solely on the provided corpus: the Wikipedia article “Automobile Club de l'Ouest”. No external sources, such as primary archives, autobiographies, period programmes, or specialist publications, were consulted.