Yet within the industry, Southwest Airlines ( LUV 1.42% ) has long stood out from the crowd. The airline looks a lot different than it did back in the early 1970s, when Southwest took advantage of a gap in federal regulatory coverage to offer intrastate air travel between key cities within the state of Texas. Once airline deregulation became reality, Southwest began to broaden its scope, moving first to serve key U.S. markets outside Texas and then looking beyond the nation's borders. Currently, Southwest helps travelers visit more than 100 destinations in the U.S. along with 10 countries internationally. Key cities include Chicago, Baltimore, Las Vegas, Denver, and Southwest's home market in Dallas. Southwest now counts itself among the top airlines in the nation, and it's No. 11 on Fortune 's list of the World's Most Admired Companies in 2019.