Lou Groen, a McDonald's franchisee in Ohio in the 1960s, struggled during Lent, as most customers avoided hamburgers, which led Groen to invent a breaded fish sandwich to appeal to the Catholic masses (per Smithsonian Magazine). CEO Ray Kroc proposed that if Groen's fish sandwich could beat out Kroc's own "Hula Burger" in sales, he would make Groen's sandwich permanent on the menu.