Finally, American Airlines and US Airways have merged, making Fort Worth the home of the airline industry’s largest carrier.This event has been two years in the making. AMR Corp., American’s now-former parent, filed for bankruptcy on Nov. 29, 2011, and by the following January, US Airways CEO Doug Parker confirmed that his company was exploring a merger.The journey through the bankruptcy process and getting the U.S. Justice Department to settle an antitrust suit has been a long one. But as Parker, now CEO of the combined airline, has said, the really hard work is ahead.The merger became effective Monday, and shares of the new American began NASDAQ trading with the ticker symbol AAL. The stock rose 65 cents, or 2.71 percent, to end the day at $24.60.It’s clear from their interviews with Star-Telegram reporter Andrea Ahles that Parker and his executive team look forward to the challenge of integrating the two airlines, albeit with a healthy degree of trepidation.“The challenge for 2014 will be to deliver on what we told everyone that we would,” said Scott Kirby, American’s new president.The first challenge is to integrate the two airlines’ operations while not inconveniencing travelers. As Beverly Goulet, chief integration officer, puts it, “do it in such a way that is not at all disruptive to the customer.”For long-term success, it will be equally important to keep the new airline’s 100,000 workers worldwide working as a team.Elise Eberwein, executive vice president for people and communications, said American must “figure out how we are going to create a culture here at an airline that allows people to feel like they’re part of something bigger than themselves.”Perhaps the biggest failure of the former American was the entrenched adversity and sometimes deep-seated distrust between workers — from mechanics to flight attendants to reservations and gate agents to pilots — and top-level executives.The greatest opportunity that Parker and his team have is to create a fresh start for everyone at American, employees and customers alike.It’s a tough task, but it’s one befitting the leaders of the world’s top airline.