From: "Beyond Stupidity" blog

The Wright Amendment

Dallas: Thw world of aviation is filled with strange protectionist laws, but none is stranger or more questionable that the infamous "Wright Amendment" and it's cousin the "Shelby Amendment".

When Dallas and Ft. Worth set out to build a massive new airport, DFW, there was concern that airlines would be reluctant to give up flying from the far more convinient Dallas Love Field. American Airlines finally agreed to move operations to DFW in exchange for a federal law that prevented any airline from flying out of Love field to anywhere outside states bordering Texas... confused yet?

See, a fledgling airline known as Southwest had arrived on the scene and started service at Love field, much to the chagrin of the vastly more powerful AA. To this day, Southwest's home base at Dallas Love Field is prevented from offering flights to anywhere outside the hops you see on that map (although the Shelby amendment added AL and MS to the list). Even more bizarrely, you are not allowed to buy a ticket to Dallas Love Field from anywhere out side the map - so if you want to go to New York, you have to buy two separte tickets, one to, say, Little Rock, then recheck yourself onto a new flight from there to New York.

Of course, Southwest's had the last laugh, managing to overcome the burden and enjoy profitability at a time when AA is struggling. Nonetheless the cost of this law is pegged at $200 Million a year to the people of Dallas.