National I Love Lucy Day is on Oct. 15. Here are 10 facts about Lucille Ball, Desi Arnaz and their hit sitcom, "I Love Lucy," which became an American classic.

I Love Lucy, which ran from 1951 until 1957, became the first show in TV history to reach 10 million people. On it, Arnaz played Ricky Ricardo, the TV husband to his real-life wife.