The person’s name is not known, but whoever bought a pack of chewing gum at the Marsh Supermarket in Troy, Ohio on this day 40 years ago was making history. It was the first purchase of an item to be scanned into a cash register by using the Universal Product Code — much better known as the bar code. Realizing the significance of the event, the buyer returned the item — a 10-pack of Wrigley’s Juicy Fruit — which is now on display at the Smithsonian in Washington, D.C. Today, the bar code is part of everyday life for the $4.2 trillion worth of annual transactions in America’s nearly 1.1 million retail trade establishments and the 14.7 million people who work in them. You can find more facts about America’s people, places and economy from the American Community Survey at <www.census.gov>.