Who was first to write t'was the night before Christmas?

The poem is entitled "A Visit From Saint Nicholas". It's tempting to call it "Twas The Night Before Christmas" because of the immensely famous first line. The author was Clement C. Moore. For some reason some people believe Samuel Clemens wrote it.

...or...

Major Henry Livingston, Jr. (1748-1828)

entitled "Account of a Visit from St. Nicholas"

The matter is still in dispute, as you can see!