b) White Castle

White Castle, founded in 1921, is recognized as the first fast-food restaurant chain established in the U.S. It revolutionized the American food industry by introducing a new way of eating and food service. White Castle’s small, square hamburgers, known as “sliders,” became iconic, and its efficient, assembly-line style of food preparation set the standard for fast-food operations. The success of White Castle paved the way for the multitude of fast-food chains that now dominate the American culinary landscape, reflecting a significant shift in American dining habits and culture.