I'd throw Washington Irving in there too.

>One of Irving's most lasting contributions to American culture is in the way that Americans celebrate Christmas. In his 1812 revisions to A History of New York, he inserted a dream sequence featuring St. Nicholas soaring over treetops in a flying wagon, an invention which others dressed up as Santa Claus. In his five Christmas stories in The Sketch Book, Irving portrayed an idealized celebration of old-fashioned Christmas customs at a quaint English manor which depicted English Christmas festivities that he experienced while staying in England, which had largely been abandoned.

I think it was the book on customs that had such a huge impact on Dickens.