George Lucas (left, with actor Mark Hamill during filming in Tunisia) was a graduate of USC film school whose experimental student film, "Electronic Labyrinth: THX 1138 4EB," he later expanded into a feature film, "THX 1138," starring Robert Duvall. He also served as a camera operator on the Rolling Stones concert film "Gimme Shelter," and wrote and directed the autobiographical comedy-drama "American Graffiti," which was nominated for five Oscars, including Best Picture, Best Director and Best Original Screenplay.

Having directed one of the most profitable films ever made ("American Graffiti" was shot for about three-quarters of a million dollars and to date has grossed more than $200 million in theatrical and home video sales), Lucas' success still didn't guarantee him carte blanche in getting backing for his followup feature - a space opera.

With the exception of Stanley Kubrick's "2001: A Space Odyssey," Hollywood science fiction was often denigrated as childish, low-budget fluff, better known for cardboard sets and monsters with zippers. Studios rarely financed the sci-fi genre, but 20th Century Fox took a hesitant chance on Lucas, thanks to "Graffiti"'s box office appeal and multiple Academy Award nominations.

While directors like Coppola, Altman, Scorsese and Spielberg were breaking new ground in dramatic cinema in the 1970s, Lucas was determined to create a fable for a generation which, he felt, was missing the innocence and wonder of older movie classics, like the Errol Flynn swashbuckler "The Adventures of Robin Hood."

As his screenplay developed through several rewrites, Lucas incorporated universal mythic traits as documented and analyzed in Joseph Campbell's "The Hero With a Thousand Faces." Luke Skywalker's journey became that of a classic heroic figure who, aided by a wizened older mentor, encounters archetypal obstacles on his quest.

Lucas turned to artist Ralph McQuarrie to create conceptual art to aid the film's designers -- and to sell the project to a skeptical studio. McQuarrie's painting of C-3PO reflected Lucas' inspiration: The robot from the 1928 Fritz Lang classic "Metropolis."

Ralph McQuarrie's pre-production painting of a light saber fight for "Star Wars," set in the corridors of the Death Star, features an earlier concept of Darth Vader.

Alec Guinness (an Oscar-winner for "The Bridge on the River Kwai") portrayed Obi-Wan (Ben) Kenobi.

Although veteran actors Alec Guinness and Peter Cushing were enlisted, Lucas wanted to go with unknowns for the three young leads. Mark Hamill, who appeared in the TV series "The Texas Wheelers," was an ideal Luke Skywalker, and Carrie Fisher, who'd had a memorable small role in "Shampoo," was a saucy Princess Leia. But no unknown could get past Harrison Ford (featured in "American Graffiti") as the mercenary Han Solo.

Luke Skywalker was - like George Lucas had been growing up in California - a small town boy enamored with fast vehicles . . . the main difference being Luke's craft hovered in the air. But Luke also found himself grappling with the fate of the universe, thanks to the evil Dark Lord who had murdered his father. (More on that to come.)

Though the target of a desperate rescue attempt aboard the Death Star, Princess Leia didn't act like a damsel in distress, proving herself quite capable with a blaster.

Inside the Darth Vader suit was U.K. bodybuilder-actor David Prowse, who learned after the fact that his very British accent would be looped over by another actor - an uncredited James Earl Jones, whose voice became inseparable from the role.

Despite futuristic trappings like fantastic weapons, hover cars and computers, the worlds of "Star Wars" appear lived-in, dirty, used -- old. Scenes on Luke's home planet of Tatooine were filmed in Tunisia, in dwellings which have existed for centuries, and the camera barely pays attention to fantastic artifacts. This naturalistic style made the locations more believable and familiar to audiences.

Mark Hamill, Alec Guinness and crew on location outside Mos Eisley spaceport (or, what would appear to be Mos Eisley once the matte painting is completed).

With shooting scheduled on three continents, Lucas struggled with the studio over the budget, necessitating rewrites and what he felt were technical compromises. However, by building his own production shop (Industrial Light & Magic) to create the complex visual effects, Lucas was able to complete production for $11.3 million, $3 million over budget. (At left, Dennis Muren photographs X-wing fighters.)

Many on the Board of Directors at Fox reportedly hated the film (some even slept through it). But a test screening in San Francisco on May 1, 1977 seemed to bode well -- the famed opening shot of a mammoth Imperial Star Destroyer pursuing a rebel spaceship left audiences gasping and cheering.

"Star Wars" opened in 32 theatres on May 25, 1977, with 11 more screens added Memorial Day weekend. Many showed 70mm prints with 6-track Dolby Stereo, the gold standard of film projection. Buzz among sci-fi fans and comic book devotees, stoked by months of pre-release news and splashy photos in fan magazines, spilled over to audiences of all stripes -- many house records for opening day were broken.

"Star Wars" attracted big repeat business. In the days before home video and DVDs, a theatre was the only place a fan could get their "fix" -- which some did dozens of times. While theatres typically changed programs weekly, "Star Wars" was held over for weeks or months. New York's Astor Plaza played "Star Wars" for 61 weeks.

Fans are so passionate about "Star Wars" characters that some dress the part, young and not-so-young alike. There is even cross-pollination between fantasy and reality, as seen by the Imperial stormtrooper (right) rooting for the Cincinnati Bengals. Fans have also formed costuming clubs, the Rebel Legion (the good guys) and the 501st Legion (the bad guys, but they have cooler uniforms), who raise money for charities.

The "Star Wars" phenomenon was not limited to North America, but some modifications were made to accommodate other languages and cultures, and not just in marketing (notice the particularly buff Luke Skywalker in the Italian poster at left). After Belgium banned children from theatres, several cuts of violent shots -- a severed arm, the smoking remains of Luke's aunt and uncle -- were made.

The success of "Star Wars" was not unnoticed by producers, leading to a plethora of sci-fi films and TV which might never have been green-lighted otherwise, like "Starcrash," "Message From Space," "Battle Beyond the Stars," "The Black Hole," "Battlestar Galactica" and "Humanoid." Even with robots, "laser swords" and space battles, none matched "Star Wars" in popularity. (And yes, there were lawsuits!)

In Fox's contract negotiations with Lucas in 1976, the studio ceded merchandising and sequel rights, figuring they would be worth little. Yet so great was the demand at Christmas that Kenner -- unable to produce action figures in time -- sold boxes containing a coupon good for still-to-be-manufactured toys, a discomfiting package to open under a tree!

A long time ago, music came not from CDs or MP3s but from 12-inch flat vinyl platters carved with grooves -- people actually stuck needles to them, to produce rapturous sounds. Four million of these "records" were sold -- and soon, other movies tried to copy the melodic grace and energy that John Williams and the London Symphony Orchestra created for "Star Wars." Few succeeded.

Excerpt: "The Throne Room and End Title"

The record-breaking box office of "Star Wars" (along with Steven Spielberg's "Jaws," which had opened two years earlier) changed Hollywood's attitude towards the summer, which they had perceived as a desert in their release schedule.

The studios began marketing countless big-budget action and science fiction blockbusters during the summer months, with franchises like the Lucas-produced Indiana Jones films becoming "tentpoles" of the studio's release schedules.

Release strategies changed so quickly that by the time of the third entry in the "Star Wars" saga, 1983's "Return of the Jedi" (left, with Carrie Fisher and Mark Hamill), the film opened in more than 1,000 theaters (compared to the original film's 32) and set a new record for opening weekend grosses.

Fans who could not get enough of the adventures of Luke Skywalker created their own, sometimes tongue-in-cheek. Fan films became a regular staple of conventions, midnight screenings and, later, the Internet, such as "Hardware Wars" ("An intergalactic tale of romance, rebellion and household appliances"), shot in 16mm for $8,000.

In 2010 the website "Star Wars Uncut" invited fans to submit recreations of scenes from "Star Wars," albeit 15 seconds in length. Visitors to the site could then vote on the best version of each 15-second segment. The resulting compendium was a crowdsourced love letter to the film, which won an Emmy Award for Interactive Media.

In the years following the debut of "Star Wars," Lucas produced five more films set in the worlds of "a galaxy far, far away" - not to mention "Special Editions" of the original trilogy with new computer-generated effects and some editorial changes (uhm, Han shot first), and 3-D versions.

After Lucas sold rights to his company to Disney, director J.J. Abrams re-launched the saga in 2015 with a new trilogy, with stars from the original (Mark Hamill, Carrie Fisher and Harrison Ford) returning, joined by new characters. Episode VII, "The Force Awakens," extended the Skywalker saga thirty years beyond the events of "Return of the Jedi." 

Pictured: Daisy Ridley as Rey, and John Boyega as Finn, in "Star Wars: The Force Awakens."

A teaser poster for Episode VIII, "The Last Jedi," to be released in December 2017.

In addition to the latest trilogy, the saga has also spawned numerous spinoff features, TV specials, books, radio dramas, cartoons, fan films, video games, an animated series, and other media, exponentially expanding the "Star Wars" universe and characters, giving the series' many fans more opportunities to cheer, play and dream.

By CBSNews.com senior producer David Morgan