Railroad Apartment ( analogy to compartments in passenger rail cars)
A railroad apartment is an apartment with a series of rooms connecting to each other in a line. A hallway typically runs the length of the apartment or flat from the front door to the back door, outside each room. This usage is most common in New York City, San Francisco and their surrounding areas.
Railroad apartments first made an appearance in New York City in the mid-19th century, and were designed to provide a solution to urban overcrowding. Many early railroad apartments were extremely narrow and buildings were five or six stories high. Few early buildings had internal sanitation, and bathrooms emptied raw sewage into the back yard. In some cases, one family would take up residence in each room, with the hallway providing communal space.
