Rollin King and Herb Kelleher founded Southwest Airlines Co. in 1966, originally named Air Southwest Company. The airline aimed to provide affordable and enjoyable travel experiences for passengers.

Southwest Airlines Co. was founded on March 9, 1967, by Herb Kelleher and Rollin King as Air Southwest Co. It later adopted its current name in 1971 and began operating as an intrastate airline within Texas.

Southwest Airlines was founded on March 15, 1967, as Air Southwest Co. in San Antonio by Rollin King and Herb Kelleher with the intention of being a Texas intrastate airline.

Southwest Airlines was awarded a certificate of 'public convenience and necessity' by the Texas Aeronautics Commission on February 20, 1968, after a legal battle against competitors like Braniff, Trans-Texas Airlines, and Continental Airlines.

On December 7, 1970, the United States Supreme Court overturned the lower court's ruling, upholding Southwest's right to fly in Texas. This event is considered by many as the starting point of deregulation in the airline industry.

Lamar Muse was elected as President and CEO of Southwest Airlines on January 1, 1971, leading the airline through a period of transformation and growth.

On March 29, 1971, Air Southwest rebranded itself as Southwest Airlines and commenced operations on June 18, 1971, flying from Dallas Love Field to San Antonio International Airport and George Bush Intercontinental Airport in Houston.

Southwest Airlines began with an initial tendering of 650,000 shares offered at approximately $11 a share on June 8, 1971, establishing itself as a low-fare, point-to-point carrier.

On June 18, 1971, a Boeing 737 named the 'red bellied warrior' took off from Love Field in Dallas, marking the inaugural flight of Southwest Airlines. This event marked the beginning of a revolution that aimed to democratize the skies.

Southwest Airlines sold its fourth 737, making a small gain, and used the opportunity to introduce ten-minute aircraft turnarounds. This move significantly increased aircraft utilization, reduced costs, and became a key factor in the airline's success for years to come.

In February 1973, Southwest President Lamar Muse came across a full-page ad from Braniff Airlines in a local Texas paper. Braniff Airlines, a rival of Southwest, had previously tried to prevent Southwest from operating.

Dallas-Fort Worth International Airport opened in 1974, attracting business to the region and becoming a hub for corporate headquarters.

In February 1975, Southwest Airlines received emergency authorization to start service to Harlingen in the Texas's Rio Grande Valley. This move was challenged in court by Texas International (TI) but Southwest successfully operated the route.

In October 1976, Southwest Airlines received approval to expand to five more Texas cities: Austin, Corpus Christi, El Paso, Lubbock, and Midland/Odessa. Legal challenges were limited, allowing Southwest to start these new points by January 1977.

Southwest Airlines won a legal battle in a Federal appeals court in 1977, preventing its eviction from Love Field. This marked the eighth time in three years that a federal court refused to support the eviction of Southwest Airlines from Love Field.

Colleen Barrett, who had been with Southwest Airlines since 1978, became the first female president of a major airline, jointly running the company with James F. Parker.

In 1979, after the passage of the Airline Deregulation Act, Southwest Airlines expanded its services nationwide, flying to adjacent states and starting service to the East and the Southeast in the 1990s.

In 1980, Southwest Airlines hired its first black pilot, Louis Freeman, and was the first to offer a frequent miles program in the mid-1980s.

In September 1981, president Howard Putnam resigned and was succeeded by Herb Kelleher at Southwest Airlines.

On February 23, 1982, Herb Kelleher was named permanent chairman, president, and chief executive officer of Southwest Airlines.

In 1983, Southwest's legal battle story was turned into a children's book, 'Gumwrappers and Goggles'.

On June 1, 1984, Southwest opened its Houston Pilot Base, marking its first crew base outside Dallas.

On November 30, 1984, Southwest Airlines received its first Boeing 737-300 aircraft.

In 1985, Southwest Airlines began flights out of St. Louis, Chicago-Midway, Phoenix, and added ski-season flights to Jackson Hole, Wyoming. The airline also returned five 727-200s as more 737-300s entered the fleet.

In 1986, Southwest Airlines Founder Herb Kelleher tested a flight simulator, emphasizing the importance of investing in high-quality training. This event highlighted the company's commitment to excellence in pilot training.

On June 18, 1987, Southwest Airlines launched its frequent-flyer program called The Company Club, which later became known as Rapid Rewards on April 25, 1996. The program rewarded trips flown regardless of distance.

Jordan started his history with Southwest Airlines in 1988 as the director of revenue accounting.

In 1989, Southwest Airlines achieved a significant milestone by surpassing the billion-dollar revenue mark.

In May 1990, Southwest Airlines added its 100th airplane, which was also a Boeing 737-500, marking a milestone for the airline.

In the early 1990s, Southwest Airlines lobbied US Congress and the Texas Legislature to oppose a high-speed rail system between Dallas, San Antonio, and Houston, and filed three lawsuits against the initiative. Southwest argued that high-speed rail would destroy the convenient and inexpensive transportation service the airlines provide.

In March 1992, Southwest Airlines and Stevens Aviation competed in an arm-wrestling match to settle a trademark dispute over the phrase 'Plane Smart'. The loser of each round was to pay $5,000 to charity, with the winner gaining the rights to the trademarked phrase.

Southwest acquired Salt Lake City-based Morris Air at the end of 1993, which facilitated its expansion into new cities in the West and Northwest.

Southwest Airlines became the first major airline to offer ticketless travel in 1994.

Southwest Airlines launched its first website, initially named 'Southwest Airlines Home Gate' which provided passengers with schedules, route maps, and company information at Iflyswa.com. The website became a significant source of revenue for the airline.

After receiving approval from the Dallas City Council, Southwest Airlines began a significant expansion of its corporate headquarters, adding 300,000 square feet at a cost of $30 million. The expansion included a new pilot training facility and additional parking space.

The Southwest Adopt-a-Pilot® Program in 1997 showcased the significant impact a dedicated Southwest guest teacher like Captain David Childs had on shaping the career path of individuals like Flight Attendant Jessica Mitchell.

By 1998, Southwest Airlines had become the 5th largest US air carrier, serving millions of passengers annually across key locations in the US.

In 1999, Southwest Airlines added its 300th Boeing 737 to its fleet, expanding its services to Connecticut and North Carolina. This milestone reflected the airline's continuous growth and commitment to expansion.

On March 5, 2000, Southwest Airlines Flight 1455, a Boeing 737-3T5, overran the runway at Burbank-Glendale-Pasadena Airport in California, skidding across a city street and coming to rest at a Chevron gas station. The accident resulted in injuries to passengers and crew, as well as significant damage to the aircraft.

On September 11, 2001, Southwest Airlines vowed to avoid layoffs and faced the challenges of the 9/11 terrorist attacks together as a close-knit family.

On September 14, 2001, Southwest Flight 145 departed from Nashville, Tennessee, with forty-nine passengers.

By 2002, Southwest hit a fleet count of 375 planes and carried over 60 million passengers.

In May 2003, Southwest Airlines achieved the top spot in the monthly domestic originating passenger rankings for the first time.

Gary C. Kelly became the CEO of Southwest Airlines on July 15, 2004, replacing former CEO Jim Parker.

In 2005, Southwest Airlines exceeded 3,000 daily flights and initiated a significant campaign to repeal the Wright Amendment, seeking more operational freedom at Dallas-Love Airport.

Southwest Airlines began service to Denver in 2006, which has become one of its most popular destinations.

In January 2007, Southwest Airlines terminated its codeshare arrangement with Icelandair after the latter ended its service from Baltimore to Keflavík International Airport.

On March 6, 2008, Federal Aviation Administration inspectors alleged that Southwest Airlines allowed 117 aircraft to fly carrying passengers despite being deemed 'not airworthy', leading to safety concerns and potential fines.

On March 12, 2008, Southwest Airlines voluntarily grounded 44 aircraft to conduct further inspections after concerns were raised about the lack of fuselage inspections on almost 60,000 flights.

On July 8, 2008, Southwest Airlines signed a codeshare agreement with WestJet of Canada, allowing the two airlines to sell seats on each other's flights.

On November 10, 2008, Southwest Airlines signed a codeshare agreement with Mexican low-cost carrier Volaris, enabling Southwest to sell tickets on Volaris flights.

On July 30, 2009, Southwest Airlines made a bid of $113.6 million for bankrupt Frontier Airlines Holdings, with plans to operate Frontier as a stand-alone carrier before potentially absorbing it.

The FAA investigated Southwest Airlines for installing improper parts on about 10% of its jets. The airline was given until December 24, 2009, to replace the parts with those approved by the FAA.

Southwest Airlines announced the acquisition of AirTran Airways on September 27, 2010. The acquisition was completed on May 2, 2011, with a transaction value of $3.2 billion.

On March 1, 2011, Rapid Rewards changed to a points system where members earn and redeem points based on a fare scale multiplier and ticket cost. The changes included no blackout dates, seat restrictions, or expiring credits.

In June 2011, a recording was released of a Southwest Airlines captain making offensive remarks towards flight attendants during an in-flight radio transmission. The pilot faced disciplinary action and diversity education before being reinstated.

Southwest Airlines placed a firm order for 150 Boeing 737 MAX aircraft on December 13, 2011, becoming the launch customer for the type.

On March 1st, 2012, Southwest and AirTran received FAA approval for a single operating certificate, a crucial step in integrating the two airlines.

Southwest received its first Boeing 737-800 on March 21st, showcasing the new addition to its fleet.

Southwest Airlines introduced the 737-800 to its fleet on April 11, 2012. The aircraft seats 175 passengers compared to the regular 143-seater 737-700.

On September 17, 2012, Southwest started the construction of a new Training and Operational Support building near its headquarters. The new facilities include a Network Operations Control building and an office/training facility.

On February 22, 2013, Southwest Airlines terminated its connecting agreement with Volaris. The termination was said to be mutual between the airlines.

On May 5, 2014, Southwest Airlines announced that it had chosen Amadeus IT Group to replace its current domestic reservation system.

On October 13, 2014, the countdown clock at Southwest Headquarters marked the end of the Wright Amendment, allowing Southwest Flight 1013 to take off from Dallas to Denver, the company's first nonstop service outside the amendment's restrictions.

On December 29th, 2014, the last AirTran Airways revenue flight, Flight 1, departed from Hartsfield-Jackson in Atlanta bound for Tampa International Airport, marking the end of an era for the airline.

On June 2, 2016, Southwest began the construction of Wings, a new office and training facility. It consists of an office building and the Leadership Education and Aircrew Development Center for pilot training.

On June 10, 2016, Southwest received approval to start flights to Cuba, launching service from Fort Lauderdale–Hollywood International Airport to Varadero and Santa Clara.

On January 10, 2017, Southwest announced changes to the company's executive leadership ranks, with Thomas M. Nealon named as president and Michael G. Van de Ven as the airline's chief operating officer.

On August 30th, 2017, Southwest received its first Boeing 737 MAX 8, the first in North America, signaling a new era in the airline's fleet modernization.

In September 2017, a woman was removed from a Southwest flight after claiming a life-threatening allergy to dogs, which were present on the aircraft. Despite requests for documentation, she was escorted off the plane by police.

On October 1, 2017, Southwest Airlines' first 737 MAX 8 aircraft began scheduled service.

In December 2017, a family was removed from a Southwest flight due to an unconfirmed head lice accusation. The family was later re-accommodated on a different flight.

On April 17, 2018, Southwest Airlines Flight 1380 experienced an engine failure resulting in the tragic death of a passenger, marking the first in-flight fatality due to an accident in Southwest's history.

On March 13, 2019, the FAA grounded all 737 MAX aircraft following incidents with Lion Air and Ethiopian Airlines, impacting Southwest's fleet and operations.

On August 16, 2019, Southwest announced the expansion of the LEAD Center to accommodate additional simulators for operational and training needs.

Since October 18, 2019, Rapid Rewards points do not expire as long as the member is alive, providing more options to use points.

On January 2, 2020, Southwest revealed the acquisition of 3 acres of land next to its Wings and LEAD facilities for future development.

On October 5, 2020, CEO Gary C. Kelly announced pay cuts for non-union employees and senior management to prevent furloughs. Southwest planned to negotiate similar cuts with pilot and flight attendant unions, despite facing opposition.

On November 6, 2020, Southwest issued WARN Act notices to 42 employees due to pandemic-related losses and stalled union negotiations, marking the first time the airline formally threatened furloughs.

The Consolidated Appropriations Act, 2021, enacted on December 27, 2020, provided additional financial aid to US airlines, leading to the rescinding of pay cuts and other measures at Southwest Airlines.

On March 11, 2021, Southwest resumed 737 MAX operations, becoming the fourth US airline to do so after the FAA formally ended the grounding of the 737 MAX aircraft.

On May 23, 2021, a female passenger assaulted a Southwest flight attendant by repeatedly punching her, causing the attendant to lose teeth. The passenger was charged with battery causing serious bodily injury.

On June 18, 2021, Southwest Airlines celebrated its fiftieth anniversary, highlighting the milestone of never having experienced employee layoffs.

On June 23, 2021, Southwest announced that Gary Kelly would transition roles in early 2022, becoming the carrier's executive chairman.

On September 14, 2021, Southwest announced that Thomas M. Nealon had decided to retire from his duties as president, with Mike Van de Ven taking over as president.

Southwest Airlines achieved its first post-pandemic profit during the fourth quarter of 2021 without federal government support.

Bob Jordan, former executive vice president of corporate services, took over as the sixth CEO of Southwest Airlines on February 1, 2022, succeeding Gary C. Kelly.

As of June 30, 2022, Southwest Airlines had 62,333 active full-time equivalent employees. The company focuses on hiring individuals with specific qualities and prioritizes employee satisfaction.

A report released on July 27, 2022, by federal investigators with the US Office of Special Counsel accused Southwest Airlines of obstructing FAA investigations, misusing safety programs, and criticized the FAA for inadequate oversight.

On September 1, 2022, Southwest Airlines Customer Representatives shifted to working entirely remotely, providing support to customers through phone, chat, and email. This transition allowed for increased flexibility in hiring new employees from across the country and scheduling current employees.

Severe delays and thousands of flight cancellations occurred during the Christmas holiday due to bad weather, inadequate staffing, and outdated employee scheduling system.

The airline initiated a massive system reset by preemptively canceling thousands of flights and halting ticket sales to address concerns of travelers buying tickets for subsequently canceled flights.

As of December 31, 2023, Southwest Airlines had 817 Boeing 737 aircraft in its fleet with an average age of approximately 11 years.

As of January 2024, Southwest Airlines flies to over 100 destinations in 42 states, Puerto Rico, Mexico, Central America, and the Caribbean, using a point-to-point system combined with a rolling-hub model.

Southwest Airlines has set a goal to achieve net zero carbon emissions by 2050, demonstrating its commitment to environmental sustainability and reducing its carbon footprint.