Don,
Air defense for the Continental US was provided by 1st (Eastern seaboard), 2nd (Northwest), 3rd (Southeast) and 4th Air Force (Southwest).
I'm sure there are websites that give more detailed info about the structure of each of them.
A second, but equally important task of these Air Forces was to provide combat crew training.
More general reading about the defense of the Americas here:
http://www.history.army.mil/brochures/DOA/DOA.htm
Regards,
Leendert