I seem to recall that security for the whole airport got tighter in the US during the first Gulf war. That's when they clamped down on cars parked in the passenger pick-up lanes, asking about bags at check-in, and ID checks to obtain boarding passes. That also coincided with the first electronic tickets, too, come to think of it.

After 9/11, almost all of the security changes were passenger-possessions only. No profiling changes (they still use CAPPS, which predates 9/11 greatly). Only bag screening seems to have changed.