Also referred to as The Run for the Roses and The Fastest Two Minutes in Sports, the Kentucky Derby is also the first jewel of the Triple Crown. And thanks to its high-spirited, hat-wearing onlookers, it is also the most fashionable of the three American thoroughbred races.

Held on the first Saturday in May at Louisville’s Churchill Downs, the Kentucky Derby draws an average of 150,000 well-heeled, well-dressed horse racing enthusiasts annually, each attendee more eager than the next to bet on the winning Kentucky Derby horse and to witness history in the making.

From Hollywood celebrities to members of the royal family and all the way down to general admission party goers whooping it up in the infield, attention to Derby style is a must. It has become acceptable for Derby fans of both sexes to don their finest ‘haute monde’ millinery or their looniest lids, all in the name of fashion and in the spirit of this most auspicious event.

What is the historical significance of wearing a hat on Derby Day?

Hats of various shape, size and functionality have been worn throughout history by both men and women. At one time it was considered proper etiquette to wear a hat outside the house and to go without one would practically reduce your social standing to that of a common beggar. In fact, it wasn’t out of the ordinary for women to change their hats several times a day, depending on where they were going and whom they were going to be seen by.

More to the point, however, hats have played an important role in the history of horse racing for centuries, dating as far back as the world famous Royal Ascot in the United Kingdom, where it is decreed that ‘all guests within the Royal Enclosure adhere to a strict dress code: male attendees must wear full morning dress including a top hat, whilst ladies must not show bare midriffs or shoulders and must wear hats’.

It didn’t take long for the royal dress code to catch on at the major racetracks in the United States. Albeit a less severe dress code than the Royal Ascot, Churchill Downs patrons taking in the Kentucky Derby in particular have been enjoying this respected tradition since 1875.

If you’re going to be in the Derby Infield, do you still have to wear a hat?

Like the Royal Ascot, there are traditional Kentucky Derby fashion rules that you should follow if you want to fit in, whether you’re planning on being in the Clubhouse, Paddock or the Infield.

For the men seated in Millionaires Row or the Clubhouse, generally acceptable attire includes solid color suits or tuxedos. Women seated in either location are expected to wear spring-themed hats and dresses in pastel colors.

Over in the infield, the same fashion rules exist but they’re taken to new extremes and they are about as relaxed as the atmosphere. Imagine tens of thousands of people dressed in their wackiest and tackiest hats. Now throw in countless bottles of bourbon and you’ve got a pretty good idea of the kind of horseplay that goes on in the Infield at the Kentucky Derby.