It’s as old as the Bible, the taking of a census. The ancient Romans did it. Medieval England did it. It’s written into our Constitution that a census be conducted once every 10 years, and yet, every 10 years, the idea of the government counting the population breeds varying levels of controversy, fear and suspicion. Which, in a way, is normal; distrust of intrusive government is encoded in the American DNA. “We’ve been doing this 200-odd years,” says census historian Margo Anderson, “and every decade, there is some issue with the census. Because it’s a fairly rare event, when the...