The smiley face knows no politics, no geography and no religion. Ball's idea was that, for at least once a year, neither should we.
Therefore, he declared that the first Friday in October each year would be recognized as World Smile Day.
Ever since the first World Smile Day was held in 1999, it's been celebrated every year in Ball's hometown of Worcester and around the world.
After his death in 2001, the Harvey Ball World Smile Foundation was created to honor his name and legacy. The foundation continues as the official sponsor of World Smile Day every year.
Now, every time World Smile Day rolls around, we can all "Do an act of kindness [and] help one person smile!"