Lyman Frank Baum (1856 - 1919) is most famous for "The Wonderful Wizard of Oz" and its sequels, a total of 14 novels in the Oz series. He also wrote this, published in 1902, a "biography" about Santa Claus - where he grew up, who raised him, how he became immortal, and (probably the biggest discovery of all) how he's able to deliver all those presents in just one night.