Quite right on the less than halcyon days of IAD back in the mid 1980s.

Just a sleepy airport back then. About the only flights then were European flights, maybe some nonstops out to West Coast. Everything else went in and out of DCA.

The Dulles access road from Tysons Corner likewise was hardly even used back then; the toll road slightly more traffic but not very much. No extension of the toll road via the Greenway to Leesburg. Highway 28 only two lane most of the way north and south of IAD. Reston was pretty much an isolated residential area; like you say, Herndon largely a quaint little old country town. But now, with 60% of the world's internet traffic going through the Dulles corridor (per Sun Microsystems friend), times have changed. Traffic, urban sprawl, high tech "campuses", and massive homebuilding all over the surrounding area (Ashburn and Countryside, e.g.) have certainly changed the character of the Loudoun County/Fairfax County boundary near IAD. We the people have managed to "Fairfax Loudoun" in opposition to the old bumper sticker.