I have chosen Victoria Station, a railway station that served as the heart of Manchester during the industrial revoluiton. During the time of the North & South era, the Victoria Station would have been the crossroads of all of those coming and going from Manchester to other cities. Likely, it would have been the arrival setting for Margaret in Manchester, or "Milton" as it is dubbed in the book. The building was actually constructed to serve as the terminus of the rail line, the gateway to the North. No further north that you could go if you were traveling in from the south. This led to the city becoming something of a melting pot of cultures and classes. Thinking about the fact that the city was such a mix of people and ideas that all had conflicting aspirations and motives, it is not hard to see how the author drew the inspiration to write and show us how Margaret and Mr. Thornton had such differing philosophies on life and class and matters of order in society.
Source: https://manchesterhistory.net/manchester/tours/tour4/area4page17.html