Jesus there are a ton of WWII and Vietnam movies.
In terms of WWII movies, "Bridge on the River Kwai" is very good indeed. Another one I always like to recommend is "The Desert Fox," if black and white is acceptable.
Edit: "The Great Escape" would probably be a good choice as well.
For non WWII stuff, "Gladiator," "Apollo 13," and "The Right Stuff," perhaps
Braveheart is pretty bad history, I feel obliged to point out. "Master and Commander"? "Rob Roy"? "Last of the Mohicans"?
Saving Private Ryan
I concur with Consuela's rec of Master and Commander and Last of the Mohicans.
The Adventures of Robin Hood (Erroll Flynn). And you can correct the history around that but it does put a lot of things in context (Angles v. Saxons, Crusades, evil authoritarian regimes)
Doctor Zhivago. The Sound of Music. Romances with a heavy historical background that drives things along.
The Best Years of Our Lives examines the experiences of soldiers returning from WWII. There are some bleak bits. One of the men lost his hands in the war and has to deal with mid-20th century prostheses and the reactions of those around him. [link]
The Adventures of Robin Hood (Erroll Flynn). And you can correct the history around that but it does put a lot of things in context (Angles v. Saxons, Crusades, evil authoritarian regimes)
Though Richard was an awful king
t history pedant
Movies of some Shakespeare plays? The Branagh Henry V perhaps?
It's for a World History course -- so not so much with movies set in America, I think? The Best Years of Our Lives is a GREAT movie though and everyone should watch it on its own merit.
My favourite historical film of all time is The Lion in Winter, but it may be too stagey and talky for this purpose. But oh, the dialog. The performances!
Gladiator sounds like a good bet. It's a decent movie with not super-violent action, interesting historical tidbits and a good character throughline.
Plenty of movies out there about the Tudors. Lots of Henry VIII stuff to choose from -- A Man for All Seasons and Anne of Thousand Days would be a good pairing for examining the same event from different perspectives.
Master and Commander - YES! While not featuring actual historical characters, it's got loads of fun details about Age of Sail Britain and it's just such an excellent film all around. I could see 15-year-old boys loving the film.
If he doesn't mind subtitled films, there is The Horseman on the Roof, which is very pretty to look at and has cool scenes about (an actual historical) cholera epidemic.
A couple of very good Australian War dramas set in early 1900's: Gallipoli and Breaker Morant.
After that, there are like a million WWII films. The Bridge on the River Kwai is on the top of that pile. I haven't seen that in ages but it's a fantastic film.
Not a movie, but: The Young Indiana Jones Chronicles? *ducking*
Thanks y'all that gives me several for him to choose from.