It’s been 80 years since the release of the Hollywood classic, Casablanca. When the film opened in 1943—just a year after the U.S. joined World War II—audiences were thrilled by its love story. Humphrey Bogart stars as the cynical owner of Rick’s Café, a nightclub in Morocco. Ingrid Bergman plays his old flame Ilsa, who’s married to a dashing Resistance leader hunted by the Nazis.

Many of the characters at Rick’s Café are European refugees trying to make their way to America. What most viewers didn’t know is that those characters were played by actors who themselves had recently fled the Nazis. This casting choice lent the film an authenticity that helped deliver its message: that a war far from our borders was a war worth waging.