A plate from the hugely influential 1909 Plan of Chicago (also known as “the Burnham Plan” after its primary author, the renowned architect and urban planner Daniel Burnham) showing proposed amendments and additions to the railroads of the city.

The thin red lines show main line railroads, which were going to be rerouted to two mega-stations to the south and west of the downtown area. To facilitate movement between these stations, an ambitious plan of subterranean streetcars (blue lines) and subway trains (dashed red lines) was proposed in addition to the already existing “L”. It’s hard to make out without viewing the image at its largest size on Flickr, but the “L” is shown by thin orange lines on the map.

In the end, little of this part of the plan was ever implemented. A new Chicago Union Station was finished in 1925, but no other stations were consolidated or relocated. In 1929, the South Branch of the Chicago River was rechanneled between Polk and 18th Streets to untangle railroad approaches as recommended by the plan. However, its importance as a part of this vastly influential document cannot be underestimated.

Source: Penn State Libraries Pictures Collection/Flickr