The event, billed as The Greatest Spectacle in Racing,[3] is considered part of the Triple Crown of Motorsport along with the 24 Hours of Le Mans and the Monaco Grand Prix, with which it typically shares a date.

The most noteworthy and most popular traditions are the 33-car field lining up three-wide for the start, the annual singing of the chorus of "Back Home Again in Indiana", and the victory lane bottle of milk.

[5] The Indianapolis Motor Speedway complex was built in 1909 as a gravel-and-tar track and hosted a smattering of small events, including ones for motorcycles.

[10] During the 1910 Decoration Day weekend, the first events on the newly paved circuit drew 60,000 spectators; Ray Harroun won the 200-mile (320 km) Wheeler-Schebler Trophy in a Marmon.

[10] The crowds grew progressively smaller for the rest of the season, however, so the track owners chose to focus on a single race, and considered a 24-hour contest, in the fashion of Le Mans, or a one-thousand-mile (1,600 km) event.

[10] They decided on 500 miles (800 km), the estimated distance a race car could run before dark descended on the track,[12] and a spectacular purse of $25,000, equivalent to 82.93 pounds (37.62 kg) of pure gold.

[15] After World War I, the native drivers and manufacturers regained their dominance of the race, and engineer Harry Miller set himself up as the most competitive of the post-war builders.

In 1946, American operatic tenor and car enthusiast James Melton started the tradition of singing "Back Home Again in Indiana" with the Purdue Band before the race when asked to do so on the spur of the moment by Speedway president Tony Hulman.

After purchasing the Speedway in 1927, Eddie Rickenbacker prohibited supercharging and increased the displacement limit to 366 cu in (6,000 cc), while also re-introducing the riding mechanic.

[26][27] With the 500 having been a part of the World Drivers' Championship between 1950 and 1960,[28][29] Ferrari made a discreet appearance at the 1952 event with Alberto Ascari,[30] but European entries were few and far between during those days.

Among the Formula One drivers who did drive at the speedway was five-time world champion Argentinian Juan Manuel Fangio, though he failed to qualify for the 1958 race.

In 1963, technical innovator Colin Chapman brought his Team Lotus to Indianapolis for the first time, attracted by the large monetary prizes, far bigger than the usual at a European event.

Brazilian Emerson Fittipaldi, Italian Teo Fabi, and Colombian Roberto Guerrero were able to obtain good outings in the 1980s, as was Dutchman Arie Luyendyk.

[41] Four local actors were hired to portray the Founding Four of James Allison, Carl Fisher, Frank Wheeler, and Arthur Newby during multiple Centennial Era events and the 100th race.

Around that same time, in the wake of the 1979 entry controversy, and the formation of CART, the race changed to an invitational event, rather than an Open, rendering the "sweepstakes" description inappropriate.

For nearly a century, the race eschewed any sort of naming rights or title sponsor, a move, though uncommon in the modern sports world, that was well received by fans.

However, officials may call for a late-race red flag (in lieu of a lengthy yellow) to provide an opportunity for a green-flag finish, an option that was used in 2014, 2019, 2022, and 2023.

While the "stock block" engines were technically legal in CART competition, they were not given the increased boost advantage, which effectively rendered them uncompetitive, and precluded their use by teams.

Following the 1955 Le Mans disaster, AAA dissolved the Contest Board to concentrate on its membership program aimed at the general motoring public.

CART and USAC occasionally quarreled over relatively minor technical regulations but utilized the same machines and the CART-based teams and driver comprised the bulk of the Indy 500 entries each year.

[54] George announced that he intended to reverse the tide of dramatic cost increases, the decreasing number of ovals in the CART series, and to allow for more opportunity for drivers from USAC sprint-car ranks.

Detractors accused George of using the 500 as leverage to allow the Speedway to gain complete control of the sport of open-wheel racing in the United States.

The move made it such that the IRL utilized different and incompatible equipment from CART; no CART-based teams would enter the Indy 500 for the next three years.

In 2000, Target Chip Ganassi Racing, still a CART-mainstay, decided to compete at Indianapolis with drivers Jimmy Vasser and Juan Pablo Montoya.

[citation needed] In the 1960s and early 1970s, the Indy 500 and the World 600 (now known as the Coca-Cola 600) at Charlotte Motor Speedway were held on different days of the week.

A few stock car drivers during that time, namely Neil Bonnett in 1979, nevertheless still attempted to qualify at Indy, even if that meant skipping Charlotte altogether.

In 2010, Bruton Smith (owner of Speedway Motorsports, Inc.), offered $20 million to any driver, IndyCar or NASCAR, who can win both the Indianapolis 500 and the Coca-Cola 600 on the same day starting in 2011, a feat that had never been accomplished.

A local dairy company executive recognized the marketing opportunity in the image and, being unaware Meyer was drinking buttermilk, offered a bottle of milk to the winners of future races.

[66] The snub led to Fittipaldi being booed during driver introductions at the next race on the schedule, held at the Milwaukee Mile in Wisconsin, a state known for its dairy industry.

However Indianapolis affiliate WRTV was required by the Speedway to blackout the national broadcast, and instead carry it on tape delay to encourage local race attendance.