This weekend, you can catch one of the most beloved movies of all time for free at the International Museum of Art. The movie starts around 2:00 p.m., and you can buy ridiculously cheap concessions to munch on while you watch the movies. The International Museum of Art is located at 1211 Montana.

Casablanca, starring Humphrey Bogart and Ingrid Bergman, is the love story to end all love stories. He's an expat American living in French Morocco, and she is the woman who broke his heart in Paris. Filming on the movie began May 25, 1942, and wrapped on August 3 of that same year. America was still reeling from the attack on Pearl Harbor and there were other world events that made the timing of Casablanca perfect.

There are a lot of things about Casablanca that are so familiar now like the lines that everyone knows by heart, but there are some interesting things about that dialogue you might not know.

1. The phrase "the usual suspects" actually originated with the movie.

2. No one actually utters the phrase, "Play it again, Sam." The phrase that comes the closest is when Ingrid Bergman says "Play it once, Sam. For old times' sake."

3. Humphrey Bogart ad-libbed the line "Here's looking at you, kid." He didn't think of it himself because it was a popular saying in the 1930s, but it wasn't written in the script.