<Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (August 2009) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (August 2009) (Learn how and when to remove this template message) </Td> </Tr> <P> A union station (also known as a union terminal and a joint station in Europe) is a railway station where tracks and facilities are shared by two or more separate railway companies, allowing passengers to connect conveniently between them . The term' union station' is used in North America and' joint station' is used in Europe . </P> <P> In the U.S., union stations are typically used by all passenger trains serving a city, although exceptions exist . For example, in Chicago, the Illinois Central and Chicago & North Western depots coexisted with Union Station . </P>

Why are all train stations called union station
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