Seabiscuit - America's Legendary Racehorse: Seabiscuit is a racehorse that has gone down as a legend in American history. Horse racing was an extremely popular sport around the time of America's Great Depression, used as an escapist form of entertainment for out-of-work laborers. This comprehensive overview of Seabiscuit's career includes many of the races for which he was most famous, as well as commentary from a number of racing enthusiasts.