What is the importance of the 91st Street Station in the novel, Crook Manifesto?

The abandoned 91st Street Station is a symbol of the history that Pepper feels has been lost to the city's development. Being forced to look at the ghost of the station on the subway summons a host of memories to Pepper, and he laments that they have been buried along with the station itself. Thus, the 91st Street Station embodies the erasure of history (often in poorer areas of the city) that occurs when certain spaces are no longer considered financially justifiable.