4-8-4 4501 4-8-4 4501 (date and location unknown) (Louis A. Marre). The Frisco Archive believes that this is St. Louis, Missouri. Continue reading...
That is at St Louis Union Station. Compare this photo taken by John Hampel in 1946: https://www.flickr.com/photos/mohistory/3442713102/ By the track diagram, I believe that is on the east lead of the west half of Union Station preparing to back in after having arrived from the west.