You've probably heard of the Christmas Light Show at the Center City Macy's - previously John Wanamaker - and if you haven't visited, now's the time. Consider it an homage to the Philadelphia of yore, when downtown shopping was the dominant paradigm and no one had heard of Walmart, let alone Amazon.

Although the Light Show dates back only to 1956, the towering department store at 13th and Market has been complementing the grandiosity of City Hall since 1911. John Wanamaker built his original store in the 1870s on the site of an old freight train depot, transforming the blocks around Market Street East into the center of the city's retail trade as at least eight imitators opened up and an arms race of amenities began.

Christmas decorations were one of the many battlefields among stores like Wanamakers, Lit Bros., Gimbel Bros., and Strawbridge & Clothier. (The Wanamakers flagship was meant to definitively distinguish it from the competition.) But the golden age of downtown department stores came to an end during the first suburbanization wave of the 1920s. The trend was put on hold by the Depression and World War II, but by the 1950s the migration of residents, shoppers, and commerce hit escape velocity.

"When the Light Show comes about, in the mid-1950s, you've got to do these really exciting things to get people to come into your store," says John Hepp, professor of history at Wilkes University and author of The Middle-Class City, a study of Philadelphia between 1876 and 1926 that focuses on Wanamakers. "It was led by PR people. This when people were worried about the effect TV is going to have, and you've got Wanamakers opening in Wilmington, Wynnewood. How do we attract people to come in? There's not a whole lot of places that have a five-story stage you can play with."

Wanamakers went out of business in 1995, but Macy's continues the Light Show tradition. Hepp argues it still serves its dual function of putting on good holiday entertainment and attracting shoppers to downtown. As Center City's population grows, along with the number of carless residents, Macy's has managed to survive while many of its downtown counterparts have failed.