For centuries, billiard balls were made of ivory from elephant tusks. But when excessive hunting caused elephant populations to decline, they began to look for alternatives. John Wesley Hyatt took up the challenge. In five years, he invented a new material called celluloid, which would become known as the first plastic. Trace the history of the material that ushered in the "plastics century." [Directed by Sharon Colman, narrated by Addison Anderson, music by Miguel d'Oliveira].