On October 15, 1951, I Love Lucy premiered on television, and after its run, it remained one of the most popular reruns in television history. To mark this landmark event in TV history, here are 5 lesser-know facts you surely didn't know about one of the greatest sitcoms of all time...  

There Is a National I Love Lucy Day October 15 is I Love Lucy Day. The unofficial holiday commemorates the day in 1951, when the show, starring real-life couple at that time, Lucille Ball and Desi Arnaz, debuted on CBS. The holiday is held just for fun and to commemorate the show. I Love Lucy is the only show in television history that has never stopped broadcasting since airing its first episode in 1951. Reruns of the show have been popular around the world ever since the show ended on May 6, 1957.

It All Started With A Radio Program In 1948, CBS went to Lucille Ball in hopes to turn her popular radio show called "My Favorite Husband" into a television program. While the radio version originally featured Richard Denning as Lucy's husband, she told the network she'd agree only if her real-life husband (Desi Arnaz) was cast in the role. Originally, the network had their doubts, but ultimately they agreed (and we bet they're glad they did!).

A Ghost Told Lucille Ball to Take The Job Prior to I Love Lucy, Lucille Ball was working in the movies. When she was offered the job, she was initially reluctant because she was concerned about the transition to television.  She needed some encouragement, which came in the form of a dream in which she saw her old friend Carole Lombard, who had died in a plane crash in 1942. In the dream, Lombard told her to go for it -- why not?? Ball said that was the moment when she knew she was making the right decision.

Smoking On Camera Was a Necessity I Love Lucy almost didn’t make it onto television because CBS had problems finding a sponsor for the series. At the last minute, the tobacco giant Philip Morris was secured as a sponsor for the show. The conditions of this were that the characters were seen smoking the Philip Morris brand of cigarettes and the name Philip Morris would be worked into the script as often as possible. Therefore, smoking was a necessity for the show to retain its sponsor.  Lucille Ball was a smoker, but she preferred Chesterfield cigarettes. In an effort to overcome this hurdle, Ball would have a stagehand that would empty packs of Philip Morris cigarettes and fill the package with Chesterfield cigarettes.

Vivian Vance Was Told to Keep Her Weight Up There is a well-known tale about Lucille Ball and Vivian Vance that says Ball did not want to be upstaged by a co-star and that she purposefully had Vance's character of Ethel decked out in drab garb. Vivian Vance even claimed that she had a contract that stated that she must always weigh more than Lucille Ball. If Lucille ever put on weight, then Vivian would have to do the same. Although it was never confirmed that this was true, both Vivian and Lucille would often bring this up on talk shows and laugh about the situation. The two woman remained friends even after their time on the show ended.