Let's not practice revisionist history here. A tragic event, 9/11, caused AA to "cough up" STL. Another airline didn't come into to SJC either. It was a government decision to allow small jets (less than 110 seats) to use some of the regional carrier slots at ORD. Thus, the F100's were shifted to ORD rather than being used at SJC (SJC wasn't a profitable destination using the larger MD-80s).