"Horse" is a book that has received so many honors from the critics, and after reading Gerardine Brook's novel, I can see why. It takes readers through three distinct eras of American history -- tied together by a magnificent thoroughbred named Lexington.  Lexington was one of the greatest racehorses the world has ever known, but more than that, he became the most successful stud the sport has ever known. But through the book "Horse," Brooks takes her readers through social issues, arts, history, science and equestrian lore that are masterfully mixed into one fascinating book.