Herb Kelleher was a San Antonio lawyer in 1967 when his client Rollin King drew a triangle on a cocktail napkin connecting Houston, Dallas, and San Antonio — three Texas cities with enough business traffic to support a low-fare intrastate carrier that the major airlines, bound by interstate regulations, would struggle to compete with directly. Kelleher took the concept seriously, raised capital, and spent the next four years in litigation as Braniff International and Texas International Airlines used every legal mechanism available to prevent Southwest from operating. The company was founded in 1967, certificated by Texas regulators in 1968, and did not fly its first commercial route until June 1971 — three years consumed entirely by legal battles initiated by incumbents. The Wright Amendment, passed by Congress in 1979 to protect American Airlines' Dallas/Fort Worth hub, restricted Southwest's operations from Love Field to destinations within Texas and adjacent states. The restriction, designed explicitly to limit Southwest's competitive reach, accidentally concentrated the airline's energy on perfecting its operations in the markets it could serve. Southwest became the most efficient short-haul carrier in America by necessity, and the operational disciplines it developed under constraint became the foundation of its national expansion after the Amendment was substantially curtailed in 2006 and fully lifted in 2014. The single aircraft type — Southwest has operated exclusively Boeing 737 variants since its founding — was a financial and operational discipline that the industry dismissed as limiting until Southwest's cost structure proved otherwise. A single aircraft type means every pilot can fly every plane, every mechanic can work on every aircraft, every spare part applies to every aircraft in the fleet. The simplicity compounds across a network of 74,000 employees and hundreds of aircraft to produce cost savings that accumulate into billions of dollars of structural advantage over carriers that operate four or five aircraft families simultaneously. The AirTran Airways acquisition in 2011 gave Southwest its first international service and access to Atlanta — Hartsfield-Jackson, the world's busiest airport and a hub Southwest had never been able to penetrate meaningfully. The integration was more complex than Southwest's management had anticipated, taking three years to fully complete and costing more than projected, but it expanded the route network into Caribbean markets and established the company's ability to execute a major carrier integration.