I am trying to find the first use of Santa Claus in an advert. I have found one from 1868 on Wikimedia, but I could not find anything to say that that was the earliest occurrence. Are they any older adverts?
This insert from Harper's Weekly issue for Dec. 24, 1862, shows Santa stuffing gifts down the chimney of a Union soldier's wife and children (upper left corner) and to encamped Union soldiers (upper right corner).
One can certainly argue that this is intended to imply that the Union cause is a righteous one, and thus that the image qualifies as a (political, non-commercial) advertisement.
Thomas Nast, the artist for both images above,
“invented” the image popularly recognized as Santa Claus. Nast first drew Santa Claus for the 1862 Christmas season Harper’s Weekly cover and center-fold illustration to memorialize the family sacrifices of the Union during the early and, for the north, darkest days of the Civil War. Nast’s Santa appeared as a kindly figure representing Christmas, the holiday celebrating the birth of Christ. His use of Santa Claus was melancholy, sad for the faltering Union war effort in which Nast so fervently believed, and sad for the separation of soldiers and families.
Likewise this cover from 10 days later clearly reinforces the message:
Thomas Nast is considered by many to be the father of the American political cartoon. He is credited with creating the elephant as the political symbol of the Republican Party and popularizing the use of a donkey for the Democratic Party. But outside of the political arena, his drawings of Santa Claus, which began during the Civil War, have had a profound and lasting effect on our modern impression of the “right jolly old elf.”
.... Guided by Clement Moore’s description of Santa Claus in “A Visit from St. Nicholas,” Nast first drew Santa during the 1862 Christmas season. ....
More surprisingly, Santa is shown amusing the soldiers by hanging a wooden effigy of Confederate president Jefferson Davis. So no one is mistaken as to its meaning, a text accompanying the drawing notes: “Santa Claus is entertaining the soldiers by showing them Jeff Davis’s future. He is tying a cord pretty tightly round his neck, and Jeff Davis seems to be kicking very much at such a fate.”