Slang For What's-What

"You travel late, neighbor. It's a dark night. Shall I bring a lantern?"

"Don't bother, the North Star is bright."

The passwords, asked and given, were signals between traveler and innkeeper that the way was clear for a shadowy figure hidden in the cargo of a horse- drawn cart to slip to shelter into a root cellar or basement.

Similar scenes were played out hundreds of times from 1833 to 1860, as runaway slaves fled to freedom via the Underground Railroad, to the North Star - the code name for Canada,...