Though the rags to riches story of its author was well on its way already, many readers in North America got their first dose of "The Boy Who Lived" 20 years ago today.

The first installment in J.K. Rowling’s groundbreaking series -- Harry Potter and the Philosopher’s Stone (or Sorcerer’s Stone in the U.S.) -- was published on Sept. 1 in 1998, a year after its original publication in England.

The series’ influence is undeniable. It turned a single mother living on welfare into a philanthropist and literary icon richer than the Queen. It sold more than 500 million copies, becoming the highest-selling book series of all time. It spawned a blockbuster film franchise, grossing nearly US$8 billion worldwide (without adjusting for inflation).

Most strikingly, the books are often credited for causing a “titanic change” in reading culture. That’s not just according to New York Times literary critic Charles Finch, who spoke with CTV News Channel on Saturday, but even research indicates the millennial generation reads more than any other generation.

“In virtually every way for children and adults the most important event of our lifetimes is Harry Potter,” said Finch. “There’s a whole range of people from the age of about 10 to 40 who fell in love with reading because of those 500 million copies.”

Finch credits the series for launching a kind of “cross pollination” of reading audiences bringing together not only children and adult readers but bringing adult themes into children’s fiction.

“Since the success of the initial book … there has been much more openness to crossover between serious subjects in young adult literature and adult readers,” he said, noting recent successful authors like John Green (The Fault in Our Stars) and Angie Thomas (The Hate U Give).

And while every Harry Potter fan will have their own personal favourites, Finch said the character with perhaps the most striking influence on a generation of readers isn’t the title character himself, but one of his sidekicks: Hermione Granger, the frizzy-haired academic played by Emma Watson in the film series, who Finch described as “a young girl who wasn’t afraid to be the smartest in class, wasn’t afraid to speak her mind.”

“It’s a huge credit to J.K. Rowling that she created this character who’s given young girls and now young women everywhere a lot of strength,” he said.