Department stores went from elite shops for wealthy people to a more accessible design in the early 20th century, but they really took off after World War II with the meteoric rise of the middle class. Then in the ‘50s, the suburban indoor shopping mall concept gathered department stores into clusters to make shopping more efficient, which drew shoppers away from downtown. But the idea of shopping for pleasure didn’t last, no matter how much "science" went into managing the experience. What killed the department store? It wasn’t just online shopping, although that played a part. You can read the history of department stores, which is really a history of the way we shop, at Collectors Weekly.
(Image credit: Barbara D’Arcy’s Bloomingdale’s Book of Home Decorating from 1973)