The Alton Junction, more commonly known as the 21st Street Crossing, is a historically significant rail location in

Chicago (''City in a Garden''); I Will , image_map = , map_caption = Interactive Map of Chicago , coordinates = , coordinates_footnotes = , subdivision_type = Country , subdivision_name ...

Illinois Illinois ( ) is a state in the Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolitan areas include, Peoria and Rockf ...

. The junction can be found just east of Canal Street and north of

Cermak Road Cermak Road, also known as 22nd Street, is a 19-mile, major east–west street on Chicago's near south and west sides and the city's western suburbs. In Chicago's street numbering system, Cermak is 2200 south, or twenty-two blocks south of the ...

near Chicago's Chinatown. It is located just south of a massive

vertical lift bridge A vertical-lift bridge or just lift bridge is a type of movable bridge in which a span rises vertically while remaining parallel with the deck. The vertical lift offers several benefits over other movable bridges such as the bascule and sw ...

that spans the South Branch of the Chicago River and "guards" the entrance to Chicago's Union Station. While a significant amount of rail traffic still traverses this interlock every day, it has been greatly reduced from using 26

diamonds Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Another solid form of carbon known as graphite is the chemically stable form of carbon at room temperature and pressure, bu ...

to control over 150 trains using the crossing. The north-south line is the former Pennsylvania Railroad ( Pittsburgh, Fort Wayne & Chicago) mainline, which is now owned and operated by

Amtrak The National Railroad Passenger Corporation, doing business as Amtrak () , is the national passenger railroad company of the United States. It operates inter-city rail service in 46 of the 48 contiguous U.S. States and nine cities in Canada ...

as the southern gateway to the Union Station complex. The

Norfolk Southern The Norfolk Southern Railway is a Class I freight railroad in the United States formed in 1982 with the merger of Norfolk and Western Railway and Southern Railway. With headquarters in Atlanta, the company operates 19,420 route miles (31, ...

's Chicago Line and the former BNSF

Southern Transcon The Southern Transcon is a main line of BNSF Railway comprising 11 subdivisions between Southern California and Chicago, Illinois. Completed in its current alignment in 1908 by the Atchison, Topeka and Santa Fe Railway, when it opened the Belen C ...

terminate at the southern entrance to the interlocking, but both NS and

Burlington Northern Santa Fe Burlington Northern Santa Fe, LLC is the parent company of the BNSF Railway (formerly the Burlington Northern and Santa Fe Railway). The company is an indirect, wholly owned subsidiary of Berkshire Hathaway, which is controlled by investor Warre ...

trains have trackage rights over the bridge to access the BNSF east-west main line. All of Amtrak's East Coast bound and

Michigan Michigan () is a U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the List of U.S. states and ...

trains use this track. The east-west line now belongs to the Canadian National Railway. It at one time was owned by Illinois Central and was the carrier's route out of its

Central Station Central stations or central railway stations emerged in the second half of the nineteenth century as railway stations that had initially been built on the edge of city centres were enveloped by urban expansion and became an integral part of the ...

to Iowa. Alton Junction was controlled by a manned interlocking tower until 2005 when Amtrak transferred control to its new Chicago Terminal control center. Known as 21st Street tower, its operators handled movements through the busy plant using a US&S Model 14 electro-pneumatic interlocking machine. In its final years 21st St took remote control of the closed NYC Clark St tower on the joint NYC/CRI&P tracks at 16th St

Notes

{{coord, 41.8538889, -87.6369444, format=dms, display=title, type:landmark_region:US-IL Transportation in Chicago Rail junctions in the United States