“After Twenty Years” is set on the streets of New York City, likely at the start of the 20th century (when O. Henry wrote the story). The story opens with Jimmy, a police officer, walking his beat in an unnamed New York City neighborhood, making sure that businesses’ doors are locked as night falls. Readers later learn that Jimmy has lived in this neighborhood his whole life, while Bob—his childhood friend—traveled west in search of both money and adventure. In the late 19th and early 20th century, “the West” was synonymous with such things in the American imagination.
It is notable that the New York restaurant where the young Jimmy and Bob promised to meet each other after 20 years apart—Big Joe Brady’s Restaurant—has closed its doors in the time since. This symbolizes the way that New York City has changed in the years since Bob left. At this time in history, the United States was navigating rapid industrialization and urbanization, as Americans flocked to cities like New York for factory jobs. It is likely that turning this family restaurant (“Big Joe Brady’s”) into an unnamed and impersonal store is O. Henry’s way of signaling the changes taking place in the city.