Beans have been cultivated since ancient times, but green bean casserole is a decidedly modern contribution to the classic Thanksgiving canon. The recipe you love was whipped up in 1955 by Dorcas Reilly , a home economist working in the Campbell's Soup Company test kitchens in Camden, New Jersey. Reilly's job was to create limited-ingredient recipes that housewives could quickly replicate (using Campbell's products, of course). Her original recipe ( still available at ), contains just six ingredients: Campbell's Cream of Mushroom soup, green beans, milk, soy sauce, pepper, and French's French Fried Onions. Her recipe was featured in a 1955 Associated Press feature about Thanksgiving, and the association has proven surprisingly durable—Campbell’s now estimates that 30 percent of their Cream of Mushroom soup is bought specifically for use in a green bean casserole.