Frederick Allen was working as a reporter at the Atlanta Journal-Constitution in 1973 when an eight-column headline on the paper’s front page piqued his curiosity.

“The thrust of it was: Anonymous Donor Gives City $10 Million Gift for Central Park,” Allen recalled during a recent interview.

When his city editor revealed the unnamed philanthropist's identity as Coca-Cola president Robert Woodruff, he was floored.

“This is in the middle of the Watergate era, when journalists are bringing down a corrupt president, and modern journalism is being born,” Allen said. “And here was a man who had that kind of power... and a major daily newspaper gladly withholding his name.”

Over the next two decades, Allen casually observed what he described as the “invisible hand" of Woodruff guiding the city, not just as a pioneering business executive, but as a generous humanitarian and perhaps most significantly, as an influential proponent of civil rights.

“There's just no exaggerating the influence that The Coca-Cola Company had on Atlanta,” Allen said.

Rick Allen

Rick Allen speaks with Coca-Cola Archivist Ted Ryan (left) and Coca-Cola Journey Editor-in-Chief Jay Moye

Amy Sparks

By the early ‘90s, the award-winning reporter and columnist turned CNN political analyst and commentator began to burn out on the daily grind of journalism. “I wanted to write books,” he said.

Woodruff, who died in 1985, would be Allen’s first subject. The first-time author was given unprecedented access to the Coca-Cola archives, as well as Woodruff’s inner circle and volume of private papers housed at Emory University’s Special Collections Library.

“It was like prospecting for gold,” he said. “It was grueling work, but every now and then a big nugget would plop into your pan.”

After several months of researching Woodruff, however, he realized he had a much bigger story to tell. At the urging of a few literary colleagues, he expanded the scope of his project from a Woodruff biography into a full-fledged history of The Coca-Cola Company. He quickly landed on both a publisher, Harper Collins, and a title, Secret Formula.

“I got to call the PR department here at The Coca-Cola Company and say, ‘Guys, this is no longer a biography of Mr. Woodruff’ – which they were perfectly happy with – ‘It's the whole company, and we're going to have to go through New Coke and into the modern era,’" Allen recalls with a chuckle. "They weren't at all happy about it.”

Rick Allen

RIck Allen inside the Coca-Cola archives in December 2015.

Amy Sparks

The book, which took four-and-a-half years to complete before being published in January 1994, was produced independently.

“There's a stigma attached to being an authorized book, and there's a stigma attached to being unauthorized,” Allen explained. “You really don't want to be either one, and so I worked fairly conscientiously to maintain an arm's length distance… I joke that the company hates my book least of all the many books that have been written about it."

The characters of Secret Formula are colorfully written, and Allen's prose is crisp and fast-moving. "Somebody once told me, 'Rick, every chapter ends in a Perils of Pauline, 'what's-going-to-happen-next cliffhanger,'" he said.

In adition to being an entertaining read, Secret Formula is regarded by many Coca-Cola historians and fans as the definitive account of what it took to build both an iconic brand and one of the world’s greatest business success stories. It has been published in seven countries and was released earlier this year as an ebook.

Click this link to listen to my full interview with Allen about what it took to bring Secret Formula to life, and why a thirst for this story still remains more than two decades after its initial pressing: