The program derives its name from the 56th garage at the Circuit de la Sarthe, which was added in 2010 to accommodate an additional entry beyond the standard grid. The Automobile Club de l'Ouest (ACO) intended this slot for vehicles "presenting a specific and innovative project." While the program was introduced in 2010, the first physical entry did not appear on the grid until two years later.
The program debuted in 2012 with the DeltaWing, a rocket-shaped prototype fielded by All-American Racers and supported by Nissan. The vehicle demonstrated significant efficiency, achieving performance levels comparable to the LMP2 class while consuming only 48% of the fuel used by traditional competitors. Its race ended six hours in following a collision with an LMP1 car.
In 2014, the Nissan ZEOD RC occupied the slot. A hybrid electric car based on the DeltaWing design, the ZEOD RC became the first vehicle to complete a full lap of Le Mans using exclusively electric power at racing speed. It also reached a top speed of 300 km/h (186.41 mph) before a gearbox issue forced its retirement after 23 minutes of racing.
The Garage 56 slot has frequently been used to advance accessibility in endurance racing. In 2016, quadruple amputee Frederic Sausset competed in a modified Morgan LMP2. Sausset attempted to return in 2020 under the SRT41 banner with an Oreca 07 LMP2 and a lineup of three disabled drivers, but the entry was cancelled due to the COVID-19 pandemic.
The SRT41 program eventually returned in 2021, marking the first Garage 56 entry in five years. The lineup included two drivers paralyzed from the waist down, who became the first disabled teammates to compete together in the history of the 24 Hours of Le Mans.
In 2023, the program featured a modified NASCAR Cup Series Next Gen Chevrolet Camaro ZL1 to celebrate the 75th anniversary of NASCAR and the centenary of the 24 Hours of Le Mans. Fielded by Hendrick Motorsports, the car was managed by Chad Knaus and bore the No. 24 as a tribute to Jeff Gordon. The driver lineup consisted of seven-time NASCAR champion Jimmie Johnson, 2009 Formula One world champion Jenson Button, and 2010 Le Mans winner Mike Rockenfeller.
The Garage 56 slot has remained empty during several editions of the race when the ACO deemed applications insufficiently mature or when teams faced technical and financial hurdles.
2013: The hydrogen-fueled GreenGT H2 was withdrawn by the team days before the race after being pronounced unfit to compete. It later performed a single demonstration lap in 2016.
2015: All applications were rejected by the ACO.
2017–2019: Welter Racing planned a biomethane-fueled prototype, the Green4U Panoz Racing GT-EV, but financial problems and the death of Don Panoz led to the program's suspension.
2019: UK-based constructor Perrinn proposed Project 424, an autonomous-capable electric LMP1, but the project did not reach the grid.
2022: The slot was once again left empty.
The program's focus on alternative power sources shares conceptual similarities with Mission 1000, a program for alternative power vehicles at the Dakar Rally.