But half asleep he rolled over, and in a voice clean and pure,
Said "Carry on, Santa, it’s Christmas Day, all secure."
One look at my watch and I knew he was right,
Merry Christmas my friend, Semper Fi and goodnight.

It is a common complaint — although not a universal one — that Christmas is too commercial. For anyone who’s waded through crowds in the weekend before Christmas, looking for the perfect gift, the idea that the modern image of Santa Claus was invented by Coca-Cola has a certain satisfactory ring to it. After all, Rudolph the Red-Nosed Reindeer was created as a holiday promotion for Montgomery Ward; in a Christmas miracle, the department store allowed the creator, Robert L. May, to have the copyright back several years later, and it made him and his brother-in-law, songwriter Johnny Marks, quite wealthy. But Santa-with-Coke advertising, memorable as it was, had very little to do with the modern conception of Santa Claus. St. Nicholas (the patron saint of thieves, pawnbrokers, and children) was a traditional German Christmas figure, of course; he gave good boys and girls presents, and was accompanied by a figure who punished bad children. There was much regional variation; in northern, Protestant Germany, the Santa figure was "Kriss Kringle" (that is, "Christ Child"), and whether the naughty were given whatfor by Black Peter or Krampus (link via Drew McDermott) seems to have depended on where in Europe you lived. Three men were responsible for the modern figure. Thomas Nast, the political cartoonist who created the donkey and elephant symbols, drew him as a gift-giving elven figure and placed his workshop at the North Pole. Louis Prang, a Boston engraver and inventor of the Christmas card, nailed down his costume. And Clement Moore, the Bible professor and son of the former president of Columbia University, invented the eight tiny reindeer and all the rest when he wrote "A Visit from St. Nicholas" on Christmas Eve, 1823. The problem is that Moore apparently did no such thing; the poem was published anonymously in 1824, and like many things anonymous, its authorship was in some doubt. Moore included it in a book of his collected verse in the 1840s, and that seemed to settle the matter for everyone except the descendants of Henry Livingston, a New York farmer, politician, and amateur poet. A few years later, two of them, Stephen Livingston Thomas and Mary Van Deusen managed to put samples of Livingston’s later work in front of Vassar’s Don Foster, America’s most famous textual investigator. Foster concluded that there was no doubt that the poem was Livingstons, and comparing the two authors’ poems on similar themes (and a Christmas poem that’s unquestionably Moore’s) certainly suggests that he was right. Livingston’s name is slowly supplanting Moore’s as the true author of the piece. Amazingly enough, 150 years later, an Air Force Lieutenant Colonel named Bruce Lovely apparently took credit for a soldider’s retelling of "’Twas the Night Before Christmas". The poem, "Merry Christmas, My Friend", was by a Marine corporal, James Schmidt, who was probably less offended at the plaigarism (his authorship was easy to establish, as he’d published it in Leatherneck magazine two years before Lovely claimed to have written it) as by the fact that Lovely had stripped out Schmidt’s references to the Marine Corps:

But half asleep he rolled over, and in a voice clean and pure,
Said "Carry on, Santa, it’s Christmas Day, all secure."
One look at my watch and I knew he was right,
Merry Christmas my friend, Semper Fi and goodnight.