The first item ever scanned by a supermarket barcode was a pack of chewing gum

At 8:01am on 26 June 1974, a cashier at a Marsh supermarket in Troy, Ohio scanned a 10-pack of Wrigley's Juicy Fruit gum — the first retail product ever sold using the new Universal Product Code barcode. That pack of gum is now preserved in the Smithsonian's National Museum of American History.

— George J. Laurer, Universal Product Code — developed at IBM, first commercial scan 1974