The founding myth at Southwest Airlines is that the airline was dreamed up in a bar. A lawyer and his pilot client sketched the first route map on a cocktail napkin in 1967.

On Thursday, the lawyer in that story, Herb Kelleher, who would go on to become the co-founder, chief executive officer, and chairman of Southwest Airlines, passed away at the age of 87.

Kelleher was a celebrity CEO in his time, both because of his personality and because of the culture he created at Southwest Airlines. He was also a visionary. 

The whole point of the cocktail napkin story, for example, is that the route map Kelleher and co-founder Rollin King sketched out was all within the state of Texas. By flying between only Dallas, Houston, and San Antonio, the two men bet that their airline could escape some onerous federal regulations in effect at the time.

Between that fight and legal battles with other airlines, it took a trip to the U.S. Supreme Court even to get off the ground. But Southwest survived, thrived, and more than 50 years later, the airline is worth over $25 billion. It's now consistently rated as America's favorite airline. 

In a statement mourning his death, current Southwest CEO Gary Kelly called Kelleher "a lifelong mentor and friend," and the airline itself said he was "a pioneer, a maverick, and an innovator ... [whose] vision revolutionized commercial aviation and democratized the skies."

Kelleher also openly copied another airline with its blessing -- Pacific Southwest Airlines -- everything from the culture to flight attendant uniforms that look ridiculously sexist and anachronistic now, but which worked at the time.

"He literally brought air travel to the masses on a scale that was unimaginable," airline industry analyst Robert Mann told The New York Times.

A 1992 Inc. magazine profile said he was a "a man of extreme tenacity and depthless energy." He was described as a hard drinker who slept "four hours a night" and was a "serious chain smoker," so maybe it's surprising that he lived to the age of 87. 

Another interesting point: In that pre-internet age, he would reportedly read a couple of hundred letters from passengers each week.

Among the lasting stories that almost everyone who talks about Kelleher seems to tell, however, is what happened after Southwest started using the ad slogan "Just Plane Smart."

It turned out that another, smaller airline called Stevens Aviation had been using the same slogan. But, rather than fight it out in court, the Stevens CEO, Kurt Herwald, challenged Kelleher to arm wrestle for it. They called it the Malice in Dallas.

The letters between the two CEOs setting up the date are hilarious. (Inc. published them at the time.) Kelleher also made a big deal about training by only drinking Wild Turkey and smoking cigarettes -- and donated the proceeds to charity. 

Herwald won, but he gave the slogan to Southwest anyway, and got a mentor and friend in Kelleher in return.

Seriously, take a few seconds to watch a small part of the video of Kelleher battling Herwald at the end of this article. You'll get a sense of what the man's personality was like as he led Southwest. 

Kelleher leaves his wife of 63 years and three children (a fourth child predeceased him). He also leaves the most-loved airline in America. Not a bad legacy. Rest in peace, Herb Kelleher.