Being from the Dallas area, here's the FYI
Basically the way History works is the following:
The City of Dallas had an airport that is called Dallas Love Field
The City of Ft. Worth had an airport called Greater Southwest International
Dallas-Ft Worth was built to create one super metropolis airport between the two cities.
Greater Southwest International was tore down since part of the land was used for DFW.
When DFW opened in 1974ish, all flights from Greater Southwest International was moved to DFW.
Most Airlines from Dallas Love Field moved to DFW --EXCEPT for Southwest Airlines that choose to remain at Love Field. This angered the City of Fort Worth and DFW International Airport, which resented expanded air service at Love Field.
The City of Ft. Worth sued Southwest Airlines for not being over to DFW, however the Courts ruled as long as Love Field was remained opened, Southwest, or any other airline could operate their. And thus Continental and American Airlines each went back into Love Field operating out of 1 gate each.
Several Years down the line, Jim Wright, the Congressman from Ft. Worth pushed through the Wright Amendment that limited the amount of flights from Love Field