There was nothing exceptional at DCA prior to 9/11. The B/C gates had officially opened in '97 (IIRC), and getting in and out was a breeze. I used to arrive at the airport around 20 minutes before departure and walk right on to the plane.

Also, there were fewer departure/landing slots at the time. Congress expanded the number of slots including some over the 1250 mile barrier in 2004. The airport is still pleasant but it used to be a lot less crowded.