Happy 100th birthday, Union Station! Opened in May, 1911 by Union Pacific predecessor Oregon-Washington Railway & Navigation Company and joined soon thereafter by the Chicago, Milwaukee, St. Paul and Pacific Railroad (colloquially, the Milwaukee Road), Union Station served as the western terminus for UP and MILW trains, with GN and NP serving King Street Station across 4th Avenue. Passengers were greeted by this grand concourse just inside the main entrance on S. Jackson Street.
It's been more than 40 years since the station hosted its last train (Amtrak selected King Street as the base of its Seattle operations), but the historic structure continues to play an important role in Puget Sound transportation as the headquarters of regional transit agency Sound Transit; also, where the platforms once were located below street level, ST's Link light rail trains now stop at International District Station. Centennial celebrations are planned for May 20th.
