For the past four days, I've walked the streets of Washington, D.C., with a group of eighty-nine 8th graders and twenty other chaperones. We averaged 9 miles—walking—daily, from monument to museum to house of government and back again. Beautiful June weather also meant we encountered other tourists, which added to the crowds and waiting time. Most 13- and 14-year-olds I know aren't the most observant, patient, and thoughtful people. But that's what chaperones are for, right? To guide their behavior, to watch out for them in unfamiliar territory, to help them see the significance of their surroundings. To warn them not to hog the sidewalk so people can pass by in…