The scene where Jake refuses to surrender to New Bern originally had Jake uttering the line "get it ready" and then throwing and breaking the radio. Instead it was changed to "NUTS!"
Morse Code during the opening title says: To the Flag
"Why We Fight" was the title of a well-known series of WWII propaganda films, directed by Frank Capra.
The flag in the army compound where Heather is, is made up of only 21 stars with 13 vertical stripes as opposed to the more commonly known 50 stars and 13 horizontal stripes.