This references the narrow passageway between two houses in a large urban area likeChicago.
Also used as a shout to clear a path in a crowded area, "Gangway, coming through".
When I came home, I walked through the gangway to enter through the backdoor of the house.
It was very crowded in the hallway so I shouted gangway, to get everyone to step aside so I could pass with my sick child.