When AA began construction prior to opening their hub in June 1981, some additional Gates were built at the end of 2E for American and the 800 foot long skywalk was built connecting 2E to the rest of AA's gates in 3E.
The other terminals all had extensive seating areas at each gate. AA did not. The corridors leading to the gates in 3E were actually a lot narrower than they are today and the floor was wood parquet overlaid with red carpet as can be seen in this old photos. (Sorry about the quality, but they were taken 25 years ago with a cheap camera.)
Note: I don't think geocities allows remote linking of images, so you may have to copy and paste the URL into your browser to see the photo.
The above photo shows the corridor that led to the gate. As you can see other than a few padded benches along the windows there was no seating at all in the gate areas.
Instead, AA had two HUGE departure lounges each capable of accomodating 1000 people. One Departure Lounge was at about Gates 3, 4, and 5 and the other departure longe was at about Gates 9, 10, and 11.
Below is an overview of one of the departure lounges taken from the topof the stairs that led to the Admiral's Club.
On the right side of the picture, you can see the big Flight Arrivals/Departure Board (No TV monitors).
Here is a picture of the same Departure Lounge when it was a little busier and at the far end you can see the staircase that led up to the Admiral's Club where I took the second photo from.
I believe AA did away with the huge departure lounges and widened Terminal 3E and added seating at each gate as part of their reconstruction prior to opening their hub.