Chicago Union Station is an intercity and commuter rail terminal located in the Near West Side neighborhood of Chicago, Illinois. The station is Amtrak's flagship station in the Midwest. While serving long-distance passenger trains, it is also the downtown terminus for six Metra commuter lines. The station is just west of the Chicago River between West Adams Street and West Jackson Boulevard, adjacent to the Chicago Loop. Including approach and storage tracks, it covers about nine and a half city blocks (mostly underground, buried beneath streets and skyscrapers). The present Chicago Union Station opened in 1925, replacing an earlier station on this site built in 1881. The station is the fourth-busiest rail station in the United States, after Pennsylvania Station, Grand Central Terminal, and Jamaica station in New York City. It is Amtrak's overall fourth-busiest station, and the busiest outside of its Northeast Corridor. It handles about 140,000 passengers on an average weekday (including 10,000 Amtrak passengers) and is one of Chicago's most iconic structures, reflecting the city's strong architectural heritage and historic achievements. It has Bedford limestone Beaux-Arts facades, massive Corinthian columns, marble floors, and a Great Hall, all highlighted by brass lamps. Chicago Union Station provides direct connections to multiple transit authorities including the Chicago Transit Authority bus and Chicago L lines, Metra, Pace, Greyhound, and more within the station or within walking distance. Name Chicago Union Station is named a union station, like many train stations across the United States that were shared by several railroad companies. The station is the third union station to occupy the site between West Adams Street and West Jackson Boulevard. The station is known by the acronym CUS, as well as by its Amtrak station code CHI. Location Chicago Union Station is situated in the West Loop Gate neighborhood of the Near West Side of Chicago, just west of Chicago's Loop. The station's underground concourse and train sheds abut the Chicago River; passageways extend west beneath Canal Street to the main station building, one block over. Services Amtrak Blue Water (Chicago – Port Huron, Michigan) California Zephyr (Chicago – Emeryville) Capitol Limited (Chicago – Washington DC) Cardinal (Chicago – New York) City of New Orleans (Chicago – New Orleans) Empire Builder (Chicago – Portland/Seattle) Hiawatha Service (Chicago – Milwaukee) Illini and Saluki (Chicago – Carbondale, Illinois) Illinois Zephyr and Carl Sandburg (Chicago – Quincy) Lake Shore Limited (Chicago – New York/Boston)