Book excerpt: Before Seabiscuit there was Exterminator, a thoroughbred who won more stakes races than Man o' War and Secretariat combined, and whose staggering success would dramatically change the world of horse-racing. His success challenged the notion that American horses would never live up to Europe's meticulously charted bloodlines and made him a patriotic icon of the country after World War I. His longevity established him as one of the public's most beloved athletes and celebrities, and he appeared in ads, films, and newspapers nationwide.--