High Quality Content by WIKIPEDIA articles! Seabiscuit is a 2003 American biographical sports drama film based on the best-selling non-fiction book Seabiscuit: An American Legend by Laura Hillenbrand. The film is loosely based on the life and racing career of Seabiscuit, an undersized and overlooked thoroughbred race horse, whose unexpected successes made him a hugely popular media sensation in the United States during the Great Depression.