A staple of American childhood foods, peanut butter and jelly sandwich, or PB&J for short is a sandwich consisting of two slices of bread, one with a layer of peanut butter, and the other one with jelly or jam. Quick, easy, and affordable, the first written reference for the sandwich appeared in 1901 in the Boston Cooking School Magazine of Culinary Science and Domestic Economics.
As peanut butter and jelly were both staples of military rations during World War II, the returning soldiers helped popularize the sandwich and it quickly spread throughout the United States. Before World War II, peanuts were expensive, and usually reserved only for the rich people, typically consumed in sandwiches with pimento cheese or meat at upscale New York City tearooms.