Interesting piece from American Heritage on the 10-year anniversary of F.W. Woolworth's going out of business:
Fundamentally, the rise of chain stores like Woolworth took place in cities. On the eve of the Civil War, less than 20 percent of Americans qualified as "urban," a category that then included all persons living in towns with a population of at least 2,500. By 1920 more than half of all Americans lived in towns or cities, and the number of people living in cities of at least 8,000 had jumped from 6.2 million to 54.3 million. In this new environment, Woolworth became an anchor of the downtown business district.
It didn't happen overnight, though. As late as 1930, working-class city dwellers still did most of their shopping at corner groceries and mom-and-pop stores, where they often were allowed generous credit. A survey in 1926 revealed that chains accounted for 53 percent of grocery stores in the upscale Oak Park suburb of Chicago but just one percent of stores in the working-class towns of Joliet and Gary. The Depression changed all that, as mom-and-pops found it harder to extend credit and customers found the lower prices at chains like Woolworth impossible to resist. A survey in 1939 showed that 91 percent of lower-income shoppers were now paying cash for their purchases, having evidently abandoned the old neighborhood store for the cheaper, cash-only chains. Woolworth was a prime beneficiary.
Woolworth's closed up shop for good in 1997, but lives on through related franchises such as Foot Locker and Champ Sports.
More here (in a magazine that is itself going out of business).
Answer to titular question here.