Many people associate cacao (and chocolate) with its origins in Mexico, but few are aware that the plant itself is native to the rainforests of the northwest Amazon. Previous episodes of this season of "Plants of the Gods" traced the journey of cacao from the Amazon to Central America and then to Europe. In this episode, ethnobotanist Mark Plotkin continues to explore the captivating history of this remarkable treat, spanning from the American Revolution through the Industrial Revolution and into the 21st century.