Southwest-AirTran deal: A timeline of two airlines

1979: Southwest expands its reach beyond Texas, flying to New Orleans. That kicked off a long-steady route expansion.

1993: ValuJet Airlines is founded in Atlanta to fill a void in the air travel market after the collapse of Eastern Airlines.

1996: After fast growth and strong financial performance, the crash of ValuJet Flight 592 in the Florida Everglades, killing all 110 aboard, prompts government to temporarily ground the carrier.

1997: ValuJet, struggling since its resumption of service in late 1996, moves to buy a small Florida-based carrier called AirTran. It takes the AirTran name and Orlando headquarters as part of the merger. The new AirTran grows steadily, buys new planes and becomes a financial star in the industry.

Sept. 27, 2010: Southwest announces it will buy AirTran and enter the Atlanta market by taking over its hub here.

March 23, 2011: AirTran shareholders approve the sale.

March 28, 2011: AirTran airport workers and reservations agents vote to unionize, saying they don't want to go through a merger with Southwest without union protections.

April 26, 2011: The U.S. Department of Justice approves the merger, clearing the companies to close the deal.

What next? After closing the deal May 2, Southwest plans to gradually transition AirTran to its brand, repaint the AirTran fleet in its livery, combine frequent flier programs and bring AirTran employees into the fold. All that could take two years. During that time it will seek FAA approval for unified safety procedures, training and operations. That approval will enable Southwest to run all the operations as a single airline.