Including approach and storage tracks, it covers about nine and a half city blocks (mostly underground, beneath streets and skyscrapers, some built with the earliest usage of railway air rights).

[4] It has Bedford limestone Beaux-Arts facades, and an interior with massive Corinthian columns, marble floors, and a Great Hall, highlighted by brass lamps.

[7] Not all lines and junctions shown Unlike many major American intercity and commuter rail hubs, Union Station does not have any direct connection to local rapid transit service.

[10] It features an elevator and stairway to the Amtrak underground pedestrian tunnel, allowing commuters to pass between Union Station and the bus staging area without crossing at street level.

Tickets are available for purchase, and some Greyhound and Megabus buses pick up passengers on South Canal Street, on the east side of the station building.

The station served as a terminal for the following railroads: Some of these trains and their names have survived to present Amtrak services, such as the Empire Builder, the California Zephyr, and the Hiawatha.

It was designed with ticket offices, concourses, platforms, waiting and baggage rooms, and shops, all on a single level, meant to be easy to navigate.

[19][20][21] Located on the Chicago River, north of Roosevelt Road, it was designed in the Art Moderne style by Graham, Anderson, Probst and White in 1931.

The post office, opened four years before Union Station, utilized the rail system, funneling mail to and from the trains below.

The Great Depression and subsequent World War II halted development, but in the 1960s, work began on Gateway Center, a Modernist complex of five buildings.

The numerous stations and associated railyards and tracks surrounded the city's central business district, the Loop, and threatened its expansion.

[26] Tracks led into the station from the south, and platforms occupied a strip of land between the back of the headhouse and the bank of the Chicago River.

[7] Growth in passenger traffic, as well as a civic push to consolidate numerous railroad terminals, led to a proposal for an enlarged Union Station on the same site.

The construction of the station also involved the demolition and relocation of some previously existing buildings such as the Butler Brothers Warehouse along the Chicago River.

Illustrator Norman Rockwell captured this era with his cover painting for a December 1944 issue of The Saturday Evening Post, depicting the station jammed with Christmas travelers.

[27] After the war, the growth of highway construction and private ownership of automobiles caused a severe decline in American passenger-rail ridership, including at Union Station.

[28] In the 1990s, Lucien Lagrange Associates made some patchwork renovations, including to the Great Hall and its skylight, which had been blacked-out since World War II.

[6][31] The status protects all exteriors, rooflines, the central lightwell, vehicular drives, the Great Hall, skylight, and select interior features – balconies, porticos, corridors, lobbies, and stairs.

[32] In 2010, Amtrak (the current owners of the Chicago Union Station Company) announced plans to air-condition the Great Hall for the first time since the 1960s.

[33] That year a Chicago Tribune investigation revealed high levels of diesel soot on the underground platforms of Union Station.

[34] Metra established an "Emissions Task Force" to study this problem and recommend solutions to improve air quality in the underground areas.

[5] Custom steel lighting covers were added to top these safety/light towers, helping them blend in with the overall neoclassical style of the station.

[36] In 2011, the city held a public meeting to discuss goals for the station, aiming to accommodate the expected 40 percent growth in passengers by 2040.

[4] In June 2015, Amtrak announced that it would renovate the station, including opening up long-closed spaces and replacing the worn staircases with marble from the original quarry near Rome.

[39] The skylight, originally built in the 1920s, suffered from decades of harsh weather, leading to countless patchwork repairs, many of which blocked light from entering the Great Hall.

[15] In 2018, Riverside Investment & Development Co. released a revised plan that included a seven-story addition above Union Station, adding 404 apartments to the building.

The developers also planned to renovate the existing upper levels of Union Station's headhouse, adding 330 hotel rooms.

[41] In 2018, Amtrak announced plans to redevelop the former Fred Harvey restaurant space into a multi-level food hall, using funds from the sale of its parking garage.

[42] In March 2020, U.S. Representative for Illinois Dan Lipinski filed a bill to shift operational control of the terminal from Amtrak to Metra.

Films in which the station appears include The Sting (1973), Silver Streak (1976), On the Right Track (1981), Doctor Detroit (1983), The Untouchables (1987), The Package (1989), My Best Friend's Wedding (1997), Flags of Our Fathers (2006), Public Enemies (2009), and Man of Steel (2013).