From Cecil’s Mail:
I don’t really know, but I have a guess. It could be the same reason you don’t hear much about Terminal 4 anymore. Once upon a time, Terminal 4 was O’Hare’s “International Terminal.” Then they built Terminal 5, and gradually brought it up to speed. As soon as #5 was fully operational, #4 stopped being used for consumer travel. I have no idea if it was demolished, repurposed, or dedicated to freight or military or what, but it leaves a gap in the normal sequence that ordinary travelers are presented with.
Likewise, it would make sense that Terminal A might have been the original “only” terminal at ORD. Then they built a new one (or two), called them A and B (and maybe C), and eventually retired A. Somebody with some good journalistic skills could probably sniff out the full story.
Then we can work on finding out whatever happened to A batteries…TRM
I can’t find any source material from the proper time period, but I think Concourse A was retained for a while during construction of the new United Terminal, and demolished afterwards. I think there may have been a long-term plan to add another concourse on the north side of Terminal 1.
Terminal 4 was the temporary terminal created in part of the parking garage while the International Terminal was under construction.