Modern archaeology and the underground

Underneath Leavenworth, Kansas, is a separate little city, complete with a street, windows, and doored storefronts. The TV reporter suggests it had something to do with the Underground Railroad, which makes no sense. A commentator on Aol.com gives a more likely explanation: out on the frontier, as a rip-roaring cowtown attempted to become safe for a proper middle class, saloons, brothels and other vice businesses literally went underground. The decent folk could walk around topside, being proud of their decent little town, while down below all hell was carryin' on.

What do you think?