Pennsylvania Railroad Station, Pittsburgh, Pa.
This is a linen postcard made by the Minsky Bros. & Co, Publishing Division, Pittsburgh, Pa. I'm not sure on the exact date of printing but these date to the 1930's and 40's.
The back of the card reads...
Union Terminal of Pennsylvania R.R. lines from East, West, North and South. Over these rails glide the Famous Brodway Limited, Spirit of St. Louis, The Red Arrow, The Pittsburgher and many other new modern steamlined trains.