Construction finally got underway in 1915 and the majority of the structure was completed by 1920, however the opening was delayed another 7 years, waiting on the completion of said viaduct.
The present building is actually the third incarnation of Union Station. The original station was built just west of the current structure in 1858 and was replaced in 1871 by the second building (demolished 1927).
Plans for a third Union Station began in 1905 but construction was delayed by 10 years due to haggling between the city and the railways over a viaduct carrying the tracks in and out of the station over local streets.
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