According to the coroner, Hartack died of natural causes as a result of heart disease. He was 74.
Hartack won five Kentucky Derbies, with perhaps his most famous being his brilliant ride on Northern Dancer in the 1964 race. It was one of the great tactical rides of all time. He did racing commentary following his retirement.
A clip of the race is here. I wish the whole race were online. Perhaps it is but I haven't found it yet:
AP has more about the racing great:
Hall of Fame rider Angel Cordero didn't know Hartack well, but was aware of his accomplishments.
''I rode with him a little bit at the end of his career,'' Cordero said Tuesday. ''When I first came to this country and met him, it was like meeting a superstar -- he was a jockey everyone had heard about.
''He was very smart. And he was amazing with the whip -- he could hit a horse left-handed coming around the turn, and the horse would never go out.''
Hartack won his first race in 1952 at West Virginia's Waterford Park, and he was elected to thoroughbred racing's Hall of Fame in 1959, at the age of 26 -- the youngest person ever elected to the hall.
That's a hell of an achievement. He was that good.
That was a good thing, for he was not known as Mr. Congeniality:
"My biggest problem isn't mounts, but Billy's personality," Lang told Time magazine for a 1958 cover story. "I spend most of my time trailing around after him, apologizing to people he's insulted. He's particularly rude if he hasn't won. He's the most competitive athlete I ever saw. If he doesn't win, he won't talk to anybody."
Lang still has sharp memories of Hartack's prickly personality, and the two eventually parted ways. But Lang calls Hartack one of the great riders in racing history.
"He was just a great rider," Lang said, reached by telephone Tuesday. "He was a very, very deliberate rider. He knew what to do on a horse, and he did it well. If you were to ask me the best rider I ever saw, I'd say Eddie Arcaro a nose in front of Bill Hartack."
Hartack, for all his bullheadedness, could be charming enough under the right circumstances. "On a horse, he was all business, but if you got to know him, he was friendly," Baeza said.
Hartack obviously knew his shortcomings enough not to get himself married or have kids although he had an active social life.