This was essentially asked the other day and answered by /u/WhyIsThatPodcast, who also followed up on the lack of Christmas (and, by extension, the lack of Santa Claus) in New England until the mid-1800s.

In the same thread, I offered some additional information about the origins of Santa Claus and how it came out of the Christmas traditions in New York, which were not only different from the New England Christmas, but were different from Christmas in the American South and in England as well.

TL;DR: Santa was a product of the intermingling of Dutch culture, which has Sinterklaas delivering toys on St. Nicholas Day, and English culture, which had some modest gift-giving on Christmas Day. This intermingling resulted in a character called "Santa Claus" delivering presents on Christmas Day, and first came about in New York City and the New York and New Jersey countryside during the late 1700s and early 1800s. The modifcation of the American Santa Claus from the earlier Dutch Sinterklaas first came about through oral tradition, and this was written down and likely modified by New York author Washington Irving in the 1809 book Knickerbocker's History of New-York, updated three years later in 1812.

But much of Santa's modern depiction is the result of Clement C. Moore's poem A Visit From St. Nicholas a.k.a. "Twas the Night Before Christmas" first published in 1823, although some elements of the depiction there were drawn from Irving's work and the earlier Dutch Sinterklaas. The poem was immediately popular, and merchants and retailers in New York cashed in on "Twas the Night Before Christmas" and the Santa Claus image during the 1820s and 30s in order to sell "New Year's presents" and "Christmas presents" in their stores. Illustrations of Santa had begun to appear in bound books by 1840, while Thomas Nast's drawings of Santa Claus for Harper's Weekly in the 1860s and 70s solidified the popular image of Santa Claus, and continues to be the basis to this day, although further additions to the Santa mythology (such as Rudolph the Red-Nosed Reindeer) would come later.