Your September 2000 issue was outstanding, particularly “Mr. Smith Goes Underground,” by Thomas Mallon, about the secret government bunker beneath the great Greenbrier resort in West Virginia. I entered the Army in November 1955 and, after a stint at Fort Bliss, served the remainder of my tour as an operations officer for the Anti-Aircraft Command in Chicago. Those were the days when SAM missiles began to replace the old 90mm guns in order to ensure the safety of the denizens of Chicago and other large cities. We traced all aircraft from the Canadian border, and if we failed to receive the proper identification, one of the missile sites would be alerted. Fortunately, we never had to watch the cornfields part and the SAMs rise from the ground. Surprisingly—and it would have been particularly surprising to the people visiting the Museum of Science and Industry—our headquarters was in the museum itself, in an isolated area with an armed guard protecting the small entrance. The centerpiece of our operations was a large sheet of glass, or some glasslike substance, that permitted the tracking of all aircraft. In an amphitheater setting, our operations personnel monitored this screen 24 hours a day. Army personnel who wanted to exit through the museum had only to open a door locked from within to mingle with the tourists.