'Private Ryan's' saving grace. (Steven Spielberg's latest film 'Saving Private Ryan')

HOLLYWOOD It's every movie marketer's dream: The world's most successful director teams up with one of America's top stars -- and a red-hot Hollywood newcomer -- in a picture that has critics raving.

Here's the catch: It's a nearly three-hour, R-rated, graphically brutal depiction of a war that ended before 80% of the U.S. population was born -- and it's being released during prime popcorn-movie season.

That's the challenge facing DreamWorks, the co-producer and domestic distributor of Steven Spielberg's "Saving Private Ryan," which marches into theaters on July 24.

Few serious blockbusters

Very few serious films -- let alone period war dramas -- have ever achieved the rank of blockbuster. Dramas have accounted for just eight of the top 100 domestic grossers, …