In the 1930's, Burgoo King and Bold Venture won the Kentucky Derby and Preakness, but tendon injuries prevented them from running in the Belmont. Burgoo King remained sidelined for 23 months and Bold Venture was retired to stud and eventually sired Triple Crown winner Assault and near-miss Middletown.
In 1944 Pensive won the Kentucky Derby and Preakness. He had the lead in the Belmont, but gave way to Bounding Home, who was coming off a win in the Peter Pan, and finished 2nd by a half a length.
In 1948 Citation won the Triple Crown and became the 8th horse in 29 years to win the Crown. Since that time 21 horses would make it 2/3 of the way, but only 3 were up to the challenge.
In 1958, Tim Tam won the Fountain of Youth, Florida Derby and Derby Trial, before winning the Kentucky Derby by a 1/2 length and the Preakness by 1-1/2 lengths. Tim Tam's 8-race win streak ended as he finished 2nd by 6 lengths in the Belmont behind Cavan, who came in off a win in the Peter Pan. An injury in the Belmont forced Tim Tam's retirement.
In 1961, Carry Back won the Florida Derby, was 2nd in the Wood Memorial, and went off as the favorite in all three Triple Crown races. Carry Back won both the Kentucky Derby and Preakness by 3/4 of a length. In the Belmont, he never got into contention and finished 7th, 14 lengths behind winner Sherluck (who was 5th in Derby and Preakness).
In 1964 the great Northern Dancer won the Florida Derby, Flamingo, Blue Grass, and Remsen Stakes before winning the Derby by a neck and the Preakness by 2-3/4 lengths. Favored in the Belmont, he finished 3rd, 6 lengths behind Quadrangle (5th in the Derby and 4th in the Preakness). Today he is recognized as one of the greatest sires of all time.
In 1966 Kauai King went off as the strong favorite in all 3 races. He won the Kentucky Derby by a 1/2 length and the Preakness by 1-3/4 lengths. In the Belmont he faded in the final quarter and wound up 7 lengths behind winner Amberoid (7th in the Derby and 3rd in the Preakness).
The most controversial decision in all of Triple Crown racing took place in 1968 when Forward Pass won the Kentucky Derby via disqualification. Forward Pass was the favorite in all 3 races, but lost to Dancer's Image by 1-1/2 lengths in the Derby. Dancer's Image was later disqualified when phenylbutazone was found in his post-race urine sample. At the time, this was not a legal medication in Kentucky, although it is now. The purse was ordered redistributed which was fought over in the courts until 1972 when it was finally settled. The Kentucky Racing Commission also ordered that Forward Pass be considered the winner of the 1968 Kentucky Derby, except for pari-mutuel pay-offs, and that the trophy be awarded to his owner Calumet Farm. Forward Pass won the Preakness by 6 lengths and led in the Belmont until the 1/8 pole but was beaten by 1-1/2 length by Stage Door Johnny, winner of the Peter Pan. Stage Door Johnny broke his maiden in May, the same week Forward Pass was awarded the Kentucky Derby win. Dancer's Image did run in the Preakness and finished 3rd, but was disqualified for bumping and placed 8th.
In 1969, Majestic Prince was trained by John Longden, 1943 Triple Crown winner Count Fleet's jockey. He was unbeaten that year, including a win in the Santa Anita Derby, and went off as a favorite in all 3 races. Arts and Letters proved a worthy opponent finishing second by a neck in the Kentucky Derby and a head in the Preakness. Majestic Prince was the first unbeaten Derby champ in 47 years, since Morvich in 1922. In the Preakness, a 21-minute inquiry ensued before stewards made it official. In the Belmont, Majestic Prince fell victim to Arts and Letters, who showed enough spunk to win the Metropolitan Handicap in between the Preakness and Belmont. Majestic Prince could not catch Arts and Letters and was beaten by five lengths. Despite coming out of the Preakness with an injury that Longden said should have kept him out of the Belmont, desire for a Triple Crown win prompted his owner to run anyway. After the Belmont, he was retired with 10 starts, 9 wins and 1 place.
In 1971, an unlikely contender from Venezuela made his attempt at the Triple Crown. Canonero II won the Kentucky Derby by 3-3/4 lengths and the Preakness by 1-1/2 lengths as the co-favorite. Despite going off as the favorite in the Belmont, a pre-existing injury caught up with him as Canonero led early, but finished fourth 4-1/4 lengths behind 34-1 long shot Pass Catcher, who came into the Belmont off a 2nd place finish in the Jersey Derby less than a week before the Belmont.
In 1973, 25 years had passed and 7 horses had won the first two legs of the Triple Crown only to come up short when a big red machine known as Secretariat rewrote the history books. Seattle Slew followed Secretariat in 1977 by becoming the first horse to win the Triple Crown undefeated. In 1978, Affirmed and Alydar hooked up to make history by becoming the first horses to finish 1-2 in all three races. In the Affirmed-Alydar series a third horse, Believe It, finished third in both the Kentucky Derby and Preakness, however his trainer decided he had seen enough of Affirmed and Alydar and did not run the Belmont.
In 1979, Spectacular Bid went off as a favorite in all 3 races and won the Kentucky Derby by 2-3/4 lengths and the Preakness by 5-1/2 lengths. Bid went off as the 1-5 favorite in the Belmont, but after a misjudged ride where he became involved in a speed duel with 85-1 long shot Gallant Best, he finished third, 3-1/4 lengths behind winner Coastal, another Peter Pan winner. Legend has it that the poor finish in the Belmont was attributed to an injury sustained the night before the race when a safety pin became lodged in one of his hooves and caused the horse to run a dull race. The story is probably true because Bid finished his career with 30 starts, 26 wins, 2 seconds, and 1 third.