Chicago's relative location has changed over time with:

Chicago's relative location has changed over time mainly due to the development and expansion of its transport infrastructure. Originally, before the advent of railroads, steamboats, subways, and highways, Chicago was located on the edge of the Midwest, with limited access to transportation networks due to its location on the edge of a large lake and at a major port. As the transportation infrastructure around Chicago developed and became more efficient, so too did the city's location, becoming increasingly more central to the region and providing easier access to the rest of the Midwest. As new transportation links have been added and improved, Chicago's relative location has shifted to become more centrally located within the Midwest.