During the early 19th century, American slaves used a secret network of safe houses and travel routes to escape into free states and Canada. These passages, created with the help of abolitionists, were known as the Underground Railroad. Since most slaves were not permitted to learn how to read or write, they often used songs as code — a way of communicating that only they understood. While a lot of mystery remains around their exact meaning, it’s widely thought that the “Drinking Gourd” refers to the Big Dipper — a signal to others about which way to travel. It’s an incredible tale, which I’ve only become aware of since Colson Whitehead’s novel “The Underground Railroad” finally made it to the top of my reading stack.