The editorial was written by Francis Pharcellus Church in 1897 in response to a letter from a young girl named Virginia O'Hanlon who was skeptical about Santa Claus. The editorial became incredibly popular, and its message about the importance of belief and imagination has resonated with people ever since.
Several animated adaptations of the story have been made over the years, but the most well-known is likely the 1974 animated special from Rankin/Bass Productions, which is still enjoyed by many today.