libraries and tied up children

What do libraries have to do with tied up children? Well, if you are walking along the street towards the Library of Congress on a Friday morning, you could possibly see two women walking eight little three year olds tied to a rope. They weren't just holding onto the rope, their little hands were tied in loops on the ropes. I guess if you're going to be taking that many kids around in the city you have to make sure they're not going to run into the street or anything, but they looked like a little chain gang. I'm pretty sure their mothers don't know that's how they take field trips.
Anyway, it was a fun day with the parents. Museums are very tiring, and tomorrow is the civil war reenactment, which promises to be all sorts of fun.