Sept. 12, 1970: Nijinsky II won the St. Leger Stakes and became the 15th winner of England's triple crown. He is the last horse to have won the English triple.
Sept. 12, 1973: Fully recovered from a virus that had beset him at Saratoga, Secretariat worked five furlongs in :57 as his last preparation for the Marlboro Cup Invitational Handicap.
Sept. 13, 1974: D. Wayne Lukas won his first Thoroughbred stakes victory, saddling his own three year-old colt, Harbor Hauler, in the second division of the Foothill Stakes at Pomona to earn $6,312.
Sept. 13, 1989: Jockey Pat Day won eight of the day's nine races at Arlington International Racecourse. In his only loss, Day finished second on Wayne's by George.
Sept. 13, 2005: Sheikh Mohammed bin Rashid al Maktoum purchased a Storm Cat colt for $9.7 million at the Keeneland September Yearling Sale.
Sept. 13, 2008: Irish trainer Aidan O'Brien became the first trainer in 73 years to achieve a sweep of all five Irish Classics when Septimus powered to a 13-length triumph in the Irish Field St. Leger at the Curragh. Jack Rogers in 1935 was the last trainer to saddle winners of Ireland's 1000 and 2000 Guineas, Derby, Oaks and St Leger in the same season.
Sept. 14, 1853: West Australian won the St. Leger Stakes by three lengths and became England's first Triple Crown winner.
Sept. 14, 1959: The new $32 million Aqueduct, operated by the New York Racing Association, opened.
Sept. 14, 2001: The National Thoroughbred Racing Association and Breeders' Cup Limited announced the formation of the NTRA Charities -- New York Heroes Fund to benefit the children and spouses of the firefighters, police officers, emergency workers and other victims who perished in the Sept. 11 attacks on the World Trade Center. The organizations also dedicated the Oct. 27 Breeders' Cup World Thoroughbred Championships, to be run at Belmont Park, to the memory of those slain and their survivors.
Sept. 15, 1876: Isaac Murphy, one of the nation's greatest black jockeys, had his first career win, aboard Glentina, at the Kentucky Association meet in Lexington. Then known as Isaac Burns, Murphy later adopted the surname of his grandfather.
Sept. 15, 1973: Secretariat won the Marlboro Cup Invitational Handicap in the then-world record time of 1:45 2/5 for 1 1/8 miles. He defeated his stablemate, Riva Ridge, by 3 1/2 lengths. The winner's share of the purse, $150,000, made Secretariat a millionaire.
Sept. 15, 2001: Jockey Russell Baze, the fourth winningest rider in history behind only Laffit Pincay Jr., Bill Shoemaker and Pat Day, registered his 7,500th career victory after piloting Valid Double to victory in the third race at Bay Meadows racetrack in San Mateo, Calif.
Sept. 15, 2007: Purchased for a record $16 million as a two-year-old, The Green Monkey made his racing debut at Belmont Park and finished third in a maiden race.
Sept. 16, 1972: Sent off at odds of 1-5, Secretariat won the Futurity Stakes at Belmont Park by 1 3/4 lengths, creating a minus show pool at the track of $4,985.
Sept. 16, 1978: For the first time in history, two Triple Crown winners met in a race, the Marlboro Cup at Belmont Park. Seattle Slew, the 1977 Triple Crown winner, defeated Affirmed, the 1978 Triple Crown winner, by three lengths.
Sept. 16, 2000: Keeneland successfully executed the Thoroughbred industry's first-ever Internet auction, selling four horses on-line for a total of $109,500. There were more than 200 buyers and agents registered to bid.
Sept. 17, 1973: Penny Chenery announced that Secretariat would make his inaugural start on the turf in the Oct. 8 Man o' War Stakes at Belmont Park.
Sept. 18, 1920: Carrying the top weight of his career, 138 pounds, three-year-old Man o' War won the Potomac Handicap, conceding 24 pounds to his nearest rival, Paul Jones, and 30 pounds to the second-place finisher, Wildair.
Sept. 18, 1943: The U.S. Army occupied the grounds of Hollywood Park as part of the war effort.
Sept. 18, 1999: Jockey David Gall retired as the fourth winningest rider of all time with 7,396 victories to his credit.
(Research via National Thoroughbred Racing Association)