Southwest Airlines was incorporated in Texas and commenced Customer Service on June 18, 1971, with three Boeing 737 aircraft serving three Texas cities - Houston, Dallas, and San Antonio. Today, Southwest operates more than 500 Boeing 737 aircraft between 63 cities. Southwest topped the monthly domestic originating passenger rankings for the first time in May 2003. Yearend results for 2006 marked Southwest’s 34th consecutive year of profitability. Southwest became a major airline in 1989 when it ...