Southwest Airlines is a major American airline headquartered in Dallas, Texas. It is the world's largest low-cost carrier, and was established in 1967 by Herb Kelleher as Air Southwest Co. The airline operates more than 4,000 departures a day during peak travel season, and serves 101 destinations in the United States and ten additional countries. Southwest Airlines has a fleet of more than 700 aircraft and employs more than 60,000 people. The company has been publicly traded since 1977 and is a component of the S&P 500.