Last week began in the Boston area with reenactments of bloody battles fought 238 years ago. I got there at 5 a.m. for one of them, standing with my family near the edge of Lexington Green as dawn broke and then, a little while later, a guy on horseback (presumably supposed to be Paul Revere, although in reality he’d lost his horse by then) rode past us to Buckman Tavern to warn the gathered patriots that the British Army was not far behind.