Martin J. “Matt” Winn rarely took no for an answer.

In 1902, the Churchill Downs racing facility was in serious financial trouble and in danger of closing. Winn assembled a group of local investors, bought the track, and the right to the name the Kentucky Derby.

Later, he changed the wagering from bookmakers to a parimutuel betting system. In 1911, he changed racing forever by introducing the $2 minimum bet: In the past, the minimum pari-mutuel bet had been $5, beyond the reach of most working people.

Churchill Downs' impresario's greatest coup may have been when he persuaded Manhattan mogul owner Harry Payne Whitney to enter his filly Regret in the 1915 run for the roses. The muscular chestnut led from start to finish and came home a 2-length winner. Regret became the first filly to triumph in the Derby.

As Winn had envisioned, Regret's victory brought an avalanche of newspaper coverage to Churchill Downs' signature race. Her victory against males was a turning point in elevating the race’s popularity nationwide, and since then the Kentucky Derby has enjoyed a prestige equal to any sporting event in the world.

Regret (BloodHorse photo)

Years later, Winn reflected on that day: "The race needed only a victory by Regret to create some more coast-to-coast publicity to really put it over. She did not fail us. Regret made the Kentucky Derby an American institution."

In the spring of 1912, near the small town of Red Bank, N.J., a foal was born at Harry Payne Whitney's Brookdale Farm. By the mighty stallion Broomstick out of the great mare Jersey Lightning, she was a pretty filly with a wide, white blaze. Still, Payne was a bit disappointed since he had hoped for a colt. He named her Regret, an impulsive misnomer if ever there was one.

He was the son of New York City financier and political leader William C. Whitney.  In 1896, "Payne," as he was known, married Gertrude Vanderbilt, the eldest daughter of Cornelius Vanderbilt, uniting two families of great wealth and prestige. He received a substantial inheritance from his father as well as his uncle, Col. Oliver Hazard Payne. Whitney had major holdings in banking, tobacco, railroads, mining, oil and a powerful stable of Thoroughbreds among his array of investments.

Whitney had been named leading American owner on eight occasions, and throughout his life was the breeder of nearly 200 stakes winners. His trainer, the legendary Jim Rowe, conditioned 1908 Horse of the Year Colin.

Regret broke her maiden at first asking in the 1914 Saratoga Special. She defeated the top colt Pebbles, who would become an archrival, winning by a length with "speed in reserve" according to the Daily Racing Form.

The racing secretary assigned Regret an impost of 127 pounds when she returned to historic Saratoga Race Course a week later for the Sanford Memorial. No problem. Under jockey Joe Notter's tight hold, Regret outran a field of 11 colts to claim victory by 1 1/2 lengths. Seven days later she was back at it, churning through heavy mud at Saratoga to win the Hopeful Stakes while spotting 13 pounds to the runner-up.

Regret wins the 1914 Hopeful Stakes. (Keeneland Library-Cook)

Regret became the first horse — colt or filly — to sweep the trio of signature Saratoga races for juveniles. Only three others — Campfire (1916), Dehere (1993) and City Zip (2000) — have since accomplished that feat.

Having earned $17,390 in a span of 14 days, Whitney sent the prized filly back to his North Jersey farm. For her dominant season, Regret was rewarded with the title of champion 2-year-old filly. Her 3-year-old campaign kicked off in the 41st Kentucky Derby, though Rowe was not completely sold on the idea. The filly had not raced in 259 days.

“Trainer Rowe and I slept in the track stable all week, I won’t ever forget that experience," said Notter years later. "The roof leaked and when it rained during the six days we spent there, I got soaked. Regret went off her feed down in Louisville. She worked well enough in New Jersey, but the train ride upset her. At Churchill Downs, she worked the Derby distance first in 2:14⅗, and then three days before the race repeated her work going the distance in 2:08⅗. Mr. Rowe wondered if he should run her.”

Col. Winn eventually convinced Rowe to start the regal, unbeaten chestnut filly. She attracted overflow crowds in a pair of public breezes comparable to the full length of the 1 1/4-mile Derby.

With a reported crowd of 49,000, Regret went off as the 5-to-2 favorite in the field of 16 as the lone filly. When the flag dropped she shot like a bullet to snatch the lead. Pebbles, her chief juvenile rival, sat just off the pace and tracked Regret throughout. With Notter in the irons, Regret easily turned back Pebbles' late charge and drew clear by two lengths in the historic victory.

The gorgeous filly shaved two seconds off Old Rosebud's track and stakes record, winning in 2:05 2/5. Rowe celebrated his second score in the Derby 34 years after his victory with Hindoo in 1881. Prior to Regret, a reported 29 fillies had competed in the Derby without a win.

“Isn’t she the prettiest filly you ever saw? You know, this is the greatest race in America at the present time, and I don’t care if she ever starts again,” Whitney said after the race. “The glory of winning this event is big enough. Regret can retire to the New Jersey farm any time now.”

Regret did race on, returning to Saratoga in August for the Saranac Stakes, where she battled Finn, the winner of the Belmont, Withers and Manhattan Handicap. She was never challenged, winning in a hand ride by 1 1/2 lengths. Regret was named Horse of the Year.

The filly experienced defeat for the first time at age 4, and then again at 5, though the latter marked one of her most superlative efforts. The 1917 Brooklyn Handicap produced, arguably, one of the greatest fields ever assembled on an American racetrack at one time. The lineup included three Kentucky Derby winners – Regret, Old Rosebud, and Omar Khayyam, future Hall of Fame inductee Roamer, future leading sire Chicle, and handicap stars Borrow, Stromboli, and Boots.

Regret claimed the lead immediately, holding off challenge after challenge throughout the first 1 1/16 miles. Then Borrow came roaring down in the final strides to edge the filly by a desperate nose, setting a new American record of 1:49 2/5 for 1 1/8 miles. Regret had spotted the victor five pounds.

Regret's final competition was a handicap race on Sept. 25, 1917, at Aqueduct, which drew just one rival. She toted 127 pounds while her only challenger carried a mere 109. Despite a snug hold by Notter, Regret set a 7-furlong track record of 1:24 1/5 while winning by three lengths.

Regret was retired in 1917 with a slate of nine victories and one second in 11 starts and earnings of $35,093. Expectations were enormous for Regret as a broodmare. Unfortunately, she did not match her prowess on the track. Only one of her 10 foals, Revenge, was a stakes winner, while Penitent was stakes-placed. Regret died at age 22, on April 14, 1934. Her grave sits on a tranquil hillside of the Whitney farm, today known as Gainesway Farm, near Lexington, Ky.

Regret's legacy shines brilliantly through the annals of American racing. It was 65 years before another filly, Genuine Risk, won the roses in 1980, and only 1988 Derby victress Winning Colors has entered that exclusive club since.

Regret was inducted into the Racing Hall of Fame in 1957.