Haddon Sundblom (1899-1976) is one of those illustrators whose work I greatly respect and almost, but don't quite, love.
His Wikipedia entry offers a too-short sketch of his career. At least it makes the point that a number of other competent illustrators worked at his studio and were influenced by him; this is one of his important claims to fame.
Leif Peng has dealt with Sundblom on his blog, and you might want to click on these links.
What maintains Sundblom's fame (among illustration buffs, anyway) is the work he did for Coca-Cola. He painted many illustrations of Coke-enjoying people for print, poster and billboard advertising. But the big thing was his Santa Claus series and, to a lesser extent, the "Frosty" character -- a smiling elfin creature always posed by a bottle or glass of the beverage.
Here are examples of Sundblom's work, with a slight emphasis on his earlier illustrations.
Also from the 20's.
I respect Sundblom for his skill in portrayal and, especially, for his way of handling paint in a pleasing thick, buttery manner.
Yet something bothers me just enough that I can't place Sundblom with contemporaries such as Dean Cormwell, John La Gatta and Mead Schaeffer. Maybe it had to do with stereotyping or pigeonholing by clients and art directors. Perhaps it was Sundblom's preference. In any event, the result was that little of his work had drama or "bite" of any kind. To some degree this is like fellow Chicago illustrator Andrew Loomis whose style was somewhat similar and whose subjects were more pleasant than edgy or dramatic. This is not to say that I favor drama and edginess -- though a whiff of something like that either in subject matter or painting technique appeals to me for some reason.