Herb Kelleher, chairman of Southwest Airlines, speaks at the company’s annual shareholder meeting in Dallas. Photo: Jon Freilich/ Bloomberg News.

Herbert Kelleher rose from a San Antonio lawyer for an upstart intra-Texas airline to become co-founder and head of Southwest Airlines, revolutionizing the industry along the way. On Thursday, Kelleher died at the age of 87.

The airline made the announcement without giving a cause or place of death.

Reared in New Jersey, Herbert David Kelleher graduated from New York University Law School and practiced on the East Coast before moving to San Antonio in 1962 to open his own law firm, according to his obituary written by Southwest.

In 1967, Kelleher and his client, Rollin King, incorporated Air Southwest, Inc. with the idea of offering low-fare, intra-Texas service that would not be federally regulated. But it would take several years of legal battles with larger airlines—which Kelleher won—before Southwest, with a name change, would take off in June 1971.

One battle went to the U.S. Supreme Court, which upheld a Texas Supreme Court decision allowing Southwest to operate between Dallas, Houston and San Antonio. That was followed by a legal fight to keep Dallas Love Field open for Southwest operations, as other airlines relocated to the new Dallas/Fort Worth International Airport.

The Dallas Morning News quoted Kelleher in his super lawyer mode in 1985 as saying: “Southwest Airlines would not be in existence today had not the other carriers been so rotten, trying to sabotage us getting into business, and then trying to put us out of business once we got started. They made me angry. That’s why Southwest is still alive. I’m not going to get beaten, and I’m not going to let anyone take advantage.”

As the legend goes, Kelleher drew up the idea for the airline’s three-city service on a bar cocktail napkin. Today, Southwest is the country’s largest domestic airline, with service to almost 100 destinations, and a 45-year history of profitability unrivaled in the industry.

Stories in the Dallas newspaper and the Fort Worth Star-Telegram burnished his reputation as a maverick, pioneer and innovator, as well as a chain smoker with a penchant for Wild Turkey bourbon. The Morning News recounted how Kelleher agreed to an arm wrestling contest with the president of a South Carolina-based airline over which one had the right to use the slogan “Just Plane Smart.”

In the highly publicized “Malice in Dallas” spectacle, Kelleher suffered a rare loss. But the other airline president had such a good time, earned such great publicity, and so appreciated Kelleher not going to court over the matter, that he let Southwest use the slogan too.

Kelleher stressed exemplary customer service, believing, as Southwest put it, “The business of business is People.” His sense of humor spread to Southwest’s flight attendants.

“His vision for making air travel affordable for all revolutionized the industry, and you can still see that transformation taking place today,” Southwest CEO Gary Kelly said in a statement. “But his legacy extends far beyond our industry and far beyond the world of entrepreneurship. He inspired people; he motivated people; he challenged people—and, he kept us laughing all the way.”

The airline industry was deregulated by the federal government with the Airline Deregulation Act of 1978.

Kelleher served as Southwest Airlines executive chairman from March 1978 to May 2008 and as president and CEO from September 1981 through June 2001. Fortune magazine, which has recognized Southwest among the world’s top 10 most admired companies, once said Kelleher might be the best CEO in America.

He stepped down as chairman in 2008 after waging a successful campaign to lift a law that had constrained Southwest’s operations since the 1970s. The so-called Wright amendment protected competing Dallas/Fort Worth International Airport from losing business to Southwest, which operated from Dallas Love Field. The law, an amendment to the International Air Transportation Act of 1979, restricted passenger flights out of Love Field to locations within Texas and its four neighboring states.

Southwest continued to list Kelleher as chairman emeritus. The airline’s employees and customers took to Twitter to remember Kelleher @#HonoringHerb.

As one tweet put it: “Herbie got his wings today. Truly a sad day for @SouthwestAir.”

Southwest ended his obituary with the words, “We miss you already, Herbie.”