When she was born, Harry Payne Whitney was disappointed. A filly, not a colt. Her parentage was prestigious. Sired by Broomstick out of the mare, Jersey Lightning, but Whitney didn’t hold high hopes for her, so he named her Regret. Then came the Saratoga Special in 1914, and she defeated her number one rival, Pebbles — a colt — and barely broke a sweat.

The next year, Matt Winn, the new owner of Churchill Downs wanted to put his little race on America’s map. He knew the filly would bring the kind of fame needed to make the Kentucky Derby a household name.

That year at Churchill Downs, the once-unwanted filly turned Whitney’s regret into a cause for celebration as she became the first filly ever to win the Kentucky Derby. Beating out her fifteen male competitors, Regret made women and girls around the country proud.

A record crowd came to watch the horse — a sleek beauty with a white blaze down her face — take the title of turf queen. Gentlemen accompanied women in hats “with six-furlong brims,” according to one quipster. The crowd leapt to their feet when Regret snatched the bit and won the race by two lengths.

“Isn’t she the prettiest filly you ever saw?” Mr. Whitney asked, standing by his champion, draped in a wreath of roses.

Born at Brookdale in New Jersey, Regret was one of several horses from the fashionable East Coast stables to make the journey westward for the race this year. With a whopping $10,000 purse and Regret’s win, the once regional race vaulted onto the national stage.

“I never saw a more enthusiastic crowd,” Mr. Whitney, in a stylish pin-striped suit and Homburg hat, proclaimed.

Churchill Downs’ energetic manager, Matt Winn, added that the Kentucky Derby would be “an American Institution” after this historic day.

The win was bittersweet for Mr. Whitney and his wife, the talented sculptress Gertrude Whitney. Mrs. Whitney’s brother, Alfred Gwynne Vanderbilt, was on the recently torpedoed steamship, The Lusitania. He drowned but not before saving many lives.

*I found this information from various sources while doing research for Secrets & Spies, the third book in my “Delafield & Malloy Investigations” series. One of my favorite sources is this book: