One day, more than half a century ago, a friend of Susie Hinton’s got beat up while walking home from their high school in Tulsa, Okla.

That lit the fire under Susie, 15. She went straight to her typewriter “and just kept going and going.”

She had spent much time observing and thinking about the great divide between the cliques at her large high school — especially the ongoing rift and constant fist-fighting warfare between the greasers and the more affluent kids.

Susie wrote her first draft in one week: 40 pages, single spaced. She had envisioned a short story, but “couldn’t get in all I wanted to say.” By age 16, she had a draft with flashbacks and more details.

She didn’t have any notions of getting published. “I was just writing it because I wanted to read it,” she says. But a friend’s mother read it, and that mom knew someone who had an agent. The door opened so that “A Different Sunset,” Susie’s title at the time, could get noticed.

In a cover letter she wrote at 17, when her agent submitted the manuscript for publishing consideration, Susie Hinton pointed to “a lot of social injustice in teen-age life.” She added that she hadn’t changed her thoughts about “my Greasers” — “that you can’t judge a boy by his haircut and clothes” — but her ideas about the “Socs” (pronounced “soashes” as in “social”) had evolved. “I realize now that even the In-Crowd can have problems.”

On the day she graduated from high school in 1966, Susie learned that New York’s Viking Press wanted to publish her book. Soon after, her editor at Viking, named Velma Varner, proposed two key changes.

No. 1: Would the young author consider using her initials, S.E., rather than Susan, so as not to turn away boy readers?

(Her middle name is Eloise, which she always had trouble spelling. In fact, she was a bad speller with poor penmanship — reasons for getting a D grade in Creative Writing in high school.)

No. 2: Varner thought “A Different Sunset” was a misleading title, too sentimental. The editor suggested “The Greasers,” then “The Leather Jackets.” Next, there was consensus to go with “The Switch-blade Boys.” Then someone at Viking came up with “The Outsiders,” and the rest is lit history.

Hinton’s unflinching coming-of-age tale told in the voice of 14-year-old Ponyboy Curtis, who’s being raised by his older brothers and fellow greasers Sodapop and Darry because their parents died, has been a fixture in classrooms everywhere, to the tune of 15 million copies. Despite the fact it’s regularly challenged for its portrayal of juvenile delinquency (including violence and underage smoking), “The Outsiders” holds a solid spot on best-ever lists of young adult titles. Some 500,000 copies are still sold every year.

A special edition has been released for the novel’s 50th anniversary (Penguin, ages 12 and up, $20). Included are 35 pages of archival content, such as early correspondence between Varner and a very excited “Susie” Hinton. There are tributes penned by Francis Ford Coppola, director of the 1983 film adaptation, and by actors cast in the movie at the onset of their careers: Matt Dillon, Rob Lowe, Ralph Macchio, Emilio Estevez and “Ponyboy” C. Thomas Howell. (Patrick Swayze, Tom Cruise and Diane Lane were also among the extraordinary cast. Hinton had a small role as a hospital nurse.)

Hinton, who is visiting cities in connection with the anniversary, will be at the Decatur Library on Saturday.

While she grew up on Tulsa’s north side, “the greaser side,” Hinton says she was friends with greasers, but wasn’t one.

“I was an observer,” she says. “I never bought into the whole ‘get a label and live with it’ thing.” At her school, the greasers owned the back parking lot while the Socs had one of the front entrances. “For some reason, everybody was obeying these rules. No one was ever questioning them.”

Hinton was a tomboy. “I liked to do boy stuff. I found nothing in the girls’ culture to identify with. Girls talked about their hair and their boyfriends’ cars. I didn’t want a boyfriend’s car, I wanted my own car.” She got a Camaro around the time her book came out in 1967, when she was a freshman at the University of Tulsa.

“The Outsiders” is her best-known young adult novel among others told from a male perspective and set in Oklahoma; these include “Rumble Fish” (1975) and “Tex” (1979).

Hinton can hardly remember her life before “The Outsiders.”

“What scares me are the letters I get from all over the world saying ‘it changed my life.’ ”

But the “most joyful” aspect has been “hearing from teachers everywhere that the book has helped reluctant readers learn to love to read.”

Does she thinks the “cliques” scene has changed much for kids over the past five decades?

“Not really. I think cliques will go on forever. That’s why the book still sells.”

BOOK TALK AND SIGNING

"The Outsiders" author S.E. Hinton will speak and answer questions. 7 p.m. Nov. 19. The event is free, but Little Shop of Stories will have copies of the book for sale. Hinton will sign books after the talk and Q&A. Decatur Library auditorium, 215 Sycamore St., Decatur. 404-370-3070, ext. 2285, http://dekalblibrary.org.