Have you just seen the film? I was a bit disappointed by it Esp. as the Belmont Stakes was filmed at Keeneland (as was the match race in Seabiscuit, which was also supposed to be Belmont).
He died in 1989 and only had approx 600 registered foals (small number by today's standards). His biggest influence in the breeding shed came not through his stallion sons, but through his daughters! He is the maternal grandsire of the three greats - A.P. Indy, Gone West and Storm Cat! Who are now retired, dead and retired (in that order and I have met all 3 ) from breeding (though in Storm Cat's case, being used via AI for Racing Quarter Horses. D.Wayne Lucas, who trained Terlingua, dam of Storm Cat, said that she was the fastest horse he'd ever trained and he started out training Quarter Horses, so that's saying something!! If you've never seen a QH race, look one up - they are mental!)
If you are not talking breeding TB's then you can still use Storm Cat by AI IF you have a spare 20k in your bank account!!! There are quite a number of spotted descendants of his around and a stallion called Tuscany Apollo is his Great Grandson. Secretariat's test mare was spotted a produced a son called First Secretary !!
OH's old mare (sadly no longer with us) was a Secretariat great grand daughter - chestnut with 3 whites too - out of mare called Pretty Pollyanna by an ID stallion - anyone know anything about Pretty Pollyanna or who owned her??
My friend had a tv mare that had storm cat in her breeding. She was brought over from America and won about 8 grand racing but had a bad fall in her last race. She sold her for £350 as a broodmare in the end as kept going unlevel in front. Some lady who breeds appys