Frontier Airlines was incorporated on February 8, 1994, by a group that included executives of the original incarnation of Frontier Airlines in response to the void left by Continental Airlines' 1993 shutdown of its Denver (Stapleton) hub. Scheduled flights began five months later in July 1994 using Boeing 737-200 jetliners on routes between Denver and four destinations in North Dakota: Bismarck, Minot, Fargo and Grand Forks. By January 1995, Frontier had expanded its route network from Denver and was serving Albuquerque, New Mexico; Billings, Montana; Bismarck, N.D.; Bozeman, Montana; El Paso, Texas; Fargo, N.D.; Great Falls, Montana; Las Vegas, Nevada; Missoula, Montana; Omaha, Nebraska; and Tucson, Arizona with 737's. Like the original airline of the same name, the new Frontier operated a hub at Denver (DEN) and for the first nine years used the slogan "The Spirit of the West" which was displayed above the windows and just behind the cursive letters "Frontier" on the fuselage of their aircraft. In 1999, Frontier signed agreements to begin purchasing and leasing Airbus A318 and A319 jet aircraft and had also added Boeing 737-300 jetliners to its fleet as well. Also by September 1999, the airline was serving destinations from coast to coast in the U.S., having expanded its route network to include Atlanta (ATL); Baltimore (BWI); Bloomington/Normal, Illinois (BMI); Boston (BOS); Chicago (MDW, Midway Airport); Dallas/Fort Worth (DFW); Phoenix (PHX); Los Angeles (LAX); Minneapolis/St. Paul (MSP); New York City (LGA, LaGuardia Airport); Orlando (MCO); Portland, Oregon (PDX); Salt Lake City (SLC); San Diego (SAN); San Francisco (SFO); and Seattle (SEA), all served from its Denver hub.
In February 2015, Frontier announced that they will begin service to several destinations from Atlanta adding the airport as a focus city. In July, Frontier also began decreasing service from Washington Dulles International Airport removing the airport as a focus city. In early 2016 Frontier announced major route expansion from airports nationwide including Atlanta, Chicago, Cincinnati, Cleveland, Orlando, and Philadelphia. In June 2016, Frontier re-established service to Port Columbus International Airport. In May 2017, the airline announced opening a new crew base in Las Vegas in the fall 2017 to improve operational reliability and potentially create new jobs in Las Vegas. In December 2017, Frontier began service to Buffalo, New York, with service to Denver, Colorado, and Florida, including Miami, Fort Myers, Orlando, and Tampa.
In October 2005, JetBlue's quarterly profit had plunged from US$8.1 million to $2.7 million largely due to rising fuel costs. Operational issues, fuel prices, and low fares, JetBlue's hallmark, were bringing its financial performance down. In addition, with higher costs related to the airline's numerous amenities, JetBlue was becoming less competitive.
Also in 2010, JetBlue entered into interline booking agreements with South African Airways and American Airlines to facilitate luggage transfers between airlines for passengers with connecting flights on a different carrier. The agreement with American included JetBlue's 18 destinations not served by American and American's 12 international flights out of New York–JFK and Boston Logan. In addition, American gave JetBlue 8 round trips slots out of Washington National in D.C. and 2 out of Westchester, New York. In return, JetBlue gave American 6 round trips out of New York–JFK. The agreement with American Airlines has since ended according to JetBlue's website.
After making a codeshare agreement with Lufthansa that went into effect in 2010, jetBlue transitioned to the Sabre reservation system used by Lufthansa, enabling the airlines to sell tickets on each other's flights, transfer luggage and passengers between the two carriers, and combine frequent flyer programs,. By making use of JetBlue's North America routes as a feeder network, the agreement put Lufthansa in a position to operate quasi-hubs in New York–JFK and Boston Logan.