Some of the champions he defeated are Carry Back, Gun Bow, Bald Eagle, Tompion, Never Bend, Beau Purple, Quadrangle, Roman Brother, Crimson Satan, Jaipur, Ridan and Pia Star.
Born at Claiborne Farm near Paris, Kentucky, he was sired by a well-known racehorse who was an unproven stallion, Your Host.
Kelso's dam was the unheralded Maid of Flight (although her sire was Count Fleet and her damsire was Man o' War).
[1] Before he set foot on a track, owner Allaire du Pont had him gelded in the hopes of calming him down.
I thought a little while and then had to confess to them that, among my friends in Wilmington, I am casually spoken of as the private chaplain for the great racehorse, Kelso.
'"[3] Trained by Dr. John Lee and racing for Ms. du Pont's nom de course Bohemia Stable, Kelso, ridden by John Block, made his two-year-old debut on September 4, 1959, at Atlantic City Race Course (at that time one of the country's premier tracks).
Dr. John Lee had returned to his veterinary practice, and Kelso's new trainer was Carl Hanford (inducted into the National Museum of Racing and Hall of Fame in 2006), who handled him for the remainder of his career.
In 1960, Kelso was voted Three-Year-Old Champion Male and received the American Horse of the Year award[4] ahead of Bald Eagle.
[5] In 1962, he won a third Horse of the Year title, taking 28 of the 32 votes in the Daily Racing Form poll.
Of all the top trainers in the past that have had this honor, I may be a little bit prejudiced, but I don't think any one of them had their hands on a horse like Kelso."
One of the greatest turf writers in history, Joe Hirsch, wrote, "Once upon a time there was a horse named Kelso.
On October 15, 1983, the 26-year-old Kelso paraded prior to the start of the Jockey Club Gold Cup at Belmont Park along with champion horse Forego and the still active John Henry in front of a crowd of over 32,000 spectators.
He is buried in the equine cemetery at Allaire du Pont's Woodstock Farm in Chesapeake City, Maryland.