The praise: American Graffiti was nominated for five Academy Awards, including Best Picture, director, original screenplay, editing, and supporting actress (Candy Clark). It lost to The Sting in every category except supporting actress, where it lost to Paper Moon (Tatum O'Neal). When the American Film Institute compiled its list of the 100 best American movies ever made, American Graffiti ranked No. 77, and probably not just because it has the word "American" in the title.

The context: George Lucas was born in 1944. That means he was 18 in 1962, when American Graffiti is set, and 28 in the summer of 1972, when it was filmed. Those numbers are significant because the movie is all about nostalgia, which Hollywood has always been good at exploiting. As part of the Baby Boom generation, Lucas had millions of peers who remembered the same things he did, and who were now beginning to dominate both the filmmaking industry and the moviegoing audience.

What's more, Lucas and his fellow Baby Boomers had just experienced an astonishing decade of change and upheaval that made American Graffiti, with its late-'50s rock tunes and quaint teenage shenanigans, even more appealing. Only 11 years separate the film's 1962 setting from its 1973 release date -- but what an 11 years they were! The Vietnam War, the civil rights movement, and the various political assassinations were only a few of the most obvious disruptive things that had happened in that time. There had also been seismic shifts in the generation gap, in the way people viewed authority, and in the way pop culture was now catering to young people. For a 30-year-old, watching American Graffiti in 1973 must have been a bittersweet reminder of wow, holy crap, look how much has changed since I graduated from high school!

Lucas probably didn't realize how strong a chord his movie would strike; he just wanted to capture his fond memories of growing up in Modesto, California. He'd been motivated to write American Graffiti while making his first feature, THX 1138 (1971), when his friend and producer Francis Ford Coppola suggested he come up with something that would have mainstream appeal. Whereas THX 1138 had been an allegory about real-world problems -- and had been a financial failure -- Lucas conceived American Graffiti to be about escapism, about going back to a more pleasant time.

After some false starts and sidetracks in 1971 and early 1972, including a rejection from United Artists (who also turned down Lucas' as-yet-untitled space opera), Lucas found a home at Universal Pictures. The studio game him a budget of $600,000, which in today's money would be about $3 million -- not much, in other words. He got Universal to increase funding by about 30 percent when Coppola came on as producer; Coppola's own film The Godfather had just come out, and his name was valuable.

Coppola proved to be invaluable later on, too, when the film was finished and Universal executives started talking about doing major re-edits, even though reactions at a test screening in January 1973 had been extremely positive. At one point Coppola offered to reimburse Universal's expenditures, buy American Graffiti, and release it himself. After The Godfather cleaned up at the Oscars in March, Universal started taking Coppola more seriously and agreed to only a few minutes' worth of cuts to American Graffiti. But studio execs still wanted to release it as a TV movie, and had to be persuaded by other Universal personnel to give a proper release. They were glad they listened, insofar as it is possible for studio execs to learn things: American Graffiti opened on Aug. 1, 1973, to outstanding reviews, made $55 million worldwide, and became a cultural milestone.

The movie: On the last night of summer 1962, in an ordinary city in northern California, a group of teens who have recently graduated from high school drive around town, listen to the radio, make out with each other, and get into mischief. Do you smell that? It's Americana! (It smells like hamburgers and Buddy Holly.)

What it influenced: The 1970s were a fertile time for 1950s nostalgia, and American Graffiti arrived as this trend was beginning. The film is technically set in the 1960s, of course, but it's populated mostly by 1950s rock songs -- and besides, what we think of as "the Sixties" didn't really kick off until about 1964. From a cultural standpoint, 1962 was essentially still the '50s. The soundtrack album -- a double record with 41 tracks -- was a hit, selling 3 million copies.

Lucas came out a winner in the whole affair, with two Oscar nominations and a multi-million-dollar paycheck. The money and clout enabled him to pursue his next project, a little thing called Star Wars. He produced -- but did not write or direct -- a sequel, More American Graffiti (1979), which brought back most of the original cast but failed to make the original money or earn the original positive reviews.

The connection between American Graffiti and the TV series Happy Days is complicated and doesn't run the way you might expect. Though Happy Days starred Ron Howard and premiered in early 1974, suggesting influence from American Graffiti, it actually pre-dates the film, having begun as an unsold pilot in 1971. ABC aired it in February 1972 as part of the anthology series Love, American Style. At some point Lucas watched that pilot to see if Ron Howard, then known for playing a little kid on The Andy Griffith Show, was convincing as an 18-year-old. He was, apparently, and Lucas cast him.

After American Graffiti's success, and with the '50s-set Grease burning up the Broadway stage, ABC became newly interested in the Happy Days pilot and commissioned a series. There was no direct affiliation between Happy Days and American Graffiti, but ABC clearly wanted to remind people of the movie. "Rock Around the Clock," which opened American Graffiti, served as Happy Days' theme song for its first two seasons, and the show even used the same font in its credits.

What to look for: Despite its many characters and storylines, the film is well organized and easy to follow. I think the strict structure is a product of Lucas' film school education, in the same way that recent high school graduates tend to write essay paragraphs with an introductory sentence, three supporting sentences, and a concluding sentence.

American Graffiti has four main threads: Curt (Richard Dreyfuss) looking for the mystery blonde; Steve (Ron Howard) dealing with his girlfriend (Cindy Williams) and preparing to leave for college; John (Paul Le Mat) cruising for chicks and getting stuck babysitting a 12-year-old (Mackenzie Phillips); and Toad (Charles Martin Smith), the nerd, driving Steve's car and meeting the fiery Debbie (Candy Clark). The four male leads meet up at the beginning of the film, go their separate ways, and start to interact again near the finale. In the meantime, their stories are addressed in a series of vignettes, one scene at a time, and a comfortable rhythm develops. (Lucas originally had it even stricter than that, always going in the same order from story A to B to C to D, back to A again; that got a little looser in the final editing).

Many of the individual scenes play out like sketches, complete with humorous punch lines. Every scene moves the story forward at least a little, and every scene ends with a plot point having been accomplished. You can imagine Lucas and his co-writers, Gloria Katz and Willard Huyck, having a stack of index cards spelling out exactly what has to happen in each vignette -- as well they should, since otherwise a movie like this could be a total mess.

Apart from the presence of Harrison Ford and Lucas' evident fondness for motorized vehicles and racing, you might never guess this was the same man who later made Star Wars. There's a lengthy, unbroken take of Ron Howard and Cindy Williams talking in a car that's longer than any single shot in the entire Star Wars saga, indicative of the different philosophies at play (easy-going slice-of-life versus plot-driven space action). Then again, American Graffiti has a lot of very corny humor, which Star Wars fans know is almost exclusively the only kind of humor found in that franchise. Lucas might just be a corny kind of guy.

In the second half of the film there are a few scenes that were clearly shot in the early hours of the morning, just as dawn was breaking, but which are intended to take place while it's still nighttime. One assumes Lucas was on a tight budget and schedule and couldn't just wait to shoot those scenes at a more appropriate time of day. The most jarring juxtaposition has Toad and Debbie getting out of the car in the dawn's early light, leading us to think several hours have passed -- but then they get back into the car and no, turns out it's still the middle of the night.

The movie ends with title cards telling us what became of the main characters. If it strikes you as tonally weird and inappropriately serious, you're not alone: Lucas' co-writers didn't like it. Lucas wouldn't budge, though. He also held firm on the movie's title, which the studio wanted to change to Another Quiet Night in Modesto (Lucas' first-draft title) or Rock Around the Clock. One battle Lucas did lose, at least at first, was over the movie's running time. Universal made him cut four minutes out of it, from 112 down to 108 -- but those deleted scenes were reintroduced for the 1978 rerelease and all subsequent home-video releases.

What's the big deal: Without American Graffiti there wouldn't be any Star Wars, which is reason enough for the film to be significant. Even aside from that, though, the movie serves as a time capsule of American life in the early 1960s, just as things were about to change drastically and permanently. As Roger Ebert put it, "no sociological treatise could duplicate the movie's success in remembering exactly how it was to be alive at that cultural instant."