The first horse to win the Kentucky Derby, Preakness and Belmont Stakes since Affirmed in 1978, and just the 12th in history, ended a long-awaited 37-year drought.
And there are signs American Pharoah's Triple Crown win last year has been good for racing.
Some recently released findings show wagering on American races is up 3.1 percent through March, to $2.4 billion. Wagering on American races in 2015 was up 1.2 percent to $10.6 billion despite less race days, less races and less starters.
During American Pharoah's final race, NBC posted its highest-rated Breeders' Cup Classic telecast in 20 years — an average of 4.6 million viewers between 5:45-6 p.m., up 53 percent from 2014.
At Ashford, and at other horse farms in Kentucky, tour traffic is up.
"The interest from the general public has been much greater than we are used to," Ashford manager Dermot Ryan said. "It's probably opened many people's eyes to what these horses are up to once they leave the track."
At Oaklawn Park, where American Pharoah won the Rebel and Arkansas Derby before his Triple Crown run, attendance was up 12 percent and on-track handle was up eight percent.
"I'm sure we benefited from the 'Pharoah' effect to a certain extent," Oaklawn's director of racing David Longinotti said.