Samuel Clemens, better known as Mark Twain, was very enamored with his daughter, Susi, and remained so up to her untimely death at age 24 in 1896. In 1875, at the age of 3, she had written her first letter to Santa Claus. As a writer and loving father, Twain, couldn't stand for his young daughter to feel like her work went unheard, so he penned the following letter to "My Dear Susie Clemens" from "The Man in the Moon" himself.

The story has been widely shared since in anthologies as an endearing reminder of the spirit of Christmas and the love of parents for their children, who year after year, in various ways, manage to keep the magic alive.