An anonymous screenwriter once remarked that only difference between the classic screenwriters and the modern ones is time. Perhaps time plays a part but the talent involved and the popularity of the film certainly lends itself to giving a film the title of "classic". Would "Gone with the Wind" still be considered a classic if it starred someone besides Clarke Gable? Would "Casablanca" be a classic if it had a cast that included someone else other than Humphrey Bogart? And would these films be classics if they hadn't touched a nerve with the audience, hadn't made big money at the box office? Who knows for sure, but it's apparent that classic screenwriters were just regular hacks until the scripts they wrote contributed to producing a hit.
The classic screenwriters are those, we tend to think, who wrote many years ago, approximately in the beginning of the twentieth century. But that rule doesn't really apply. It's really the way we apply the term 'classic". We now accept a new category, that of the "modern classic". And certainly Francis Ford Coppola falls into the category of a modern classic screenwriter. Even twenty, thirty or forty years after his passing (no time soon I hope) he still won't be considered one of the "classic screenwriters". Simply because his generation was too late in the twentieth century.
The classic screenwriters -- those who plied their craft in cinema's golden age - didn't realize they were writing classics at the time. They were probably just happy to have a job. Most scripts were hammered out in a few days. Some were being written on the set while the movie was actually being filmed! Of course this being the film industry there are plenty of exceptions. But we now know there's nothing mysterious about writing a script. Film making is a collaborative effort and a lot of hands may touch and influence a script before it reaches the screen. In fact, it's doubtful that very many classic screenwriters even considered what they were doing was "art". A film script had lasting value if it led to the sale of another film script.
Talking about art we can also recognize the movie screenwriters who are writing and producing films with their eyes on the Cannes Film Festival or for the Academy Awards. These movies are always under the attention of mass media, under the eyes of other screenwriters, and when the reviews are less than stellar it's easy to say the problem lies with the talent. But the best cast in the world can't save a bad script. A god script however can allow even the worst actors to rise to another level. So maybe the question is what movies are made for money, what movies are made for big money, and what movies are made for filming power?
Francis Ford Coppola shares a space with several other classic screenwriters. If he never has another hit besides the Godfather trilogy and Apocalypse Now his place in American cinema is all but assured. If he is a classic screenwriter it's only because his films have left an indelible mark on modern cinema.
And for that he is a classic.