The new service pits the onetime scrappy underdog in head-to-head competition with American and maybe Delta for passengers traveling to and from Dallas.
Southwest announced Monday that it will fly from Love Field to five cities starting Oct. 13 and 10 more on Nov. 2.
Those routes are currently off-limits to Southwest's Boeing 737 jets because of a 1980 law designed to protect nearby Dallas-Fort Worth International Airport. Under the Wright Amendment, as the law was called, planes bigger than 56 seats could only fly from Love Field to other cities in Texas and a few nearby states.
Southwest expects to add nearly 20 flights a day, to 146 daily departures in November, from Love Field, the airline's eighth-busiest airport.
"It will mean the opportunity to grow and add airplanes and add jobs," CEO Gary Kelly said. He said the additional flying wouldn't affect earnings through 2015.
With the new long-haul routes, Southwest will compete against similar service from American Airlines Group Inc. at nearby DFW Airport.
Southwest's toughest competition, however, might come from Delta Air Lines Inc., which is already selling tickets for flights in late 2014 from Love Field to New York, Los Angeles, Atlanta, Minneapolis and Detroit.
There's just one hitch: Delta doesn't have any gates at Love Field.
American has two gates but agreed to give them up to settle a government lawsuit against its merger with US Airways. Delta wants to buy them from American, but so does Southwest, and other airlines could enter the bidding. The U.S. Justice Department has said that the gates shouldn't go to so-called legacy carriers such as Delta and United, but Delta points out that Southwest already controls 16 of the 20 gates at Love Field.
On Oct. 13, Southwest will start flying from Dallas to Chicago; Baltimore; Denver; Las Vegas; and Orlando, Fla. On Nov. 2, it will add New York's LaGuardia Airport; Washington's Reagan National Airport; Los Angeles, San Diego and Santa Ana, Calif.; Atlanta; Nashville; Fort Lauderdale and Tampa, Fla.; and Phoenix.
The fight over Love Field is a big part of the history of Southwest Airlines, which began as a Texas-only carrier. Herb Kelleher, the airline's co-founder and a lawyer who personally fought some of the legal battles, attended Monday's announcement at the airport.
"It just proves that being patient pays off," he said. "Only had to wait for 40 years."