A child browsed a grocery store in the 1940s. Syd Greenberg/FPG/Archive Photos/Getty Images Grocery shopping has changed dramatically over the last century. Supermarkets first started emerging in the 1920s, forever altering how people shop for food. Photos show the shift from small stores to supermarkets in the US. For most Americans who don't use Instacart, grocery shopping today probably doesn't look all that different from their childhoods — they may mourn the discontinued Dino Pebbles cere