According to Wikipedia, Knickerbocker, also spelled Knikkerbakker, Knikkerbacker, and Knickerbacker, is a surname that dates back to the early settlers of New Netherland that was popularized by Washington Irving in 1809 when he published his satirical A History of New York under the pseudonym "Diedrich Knickerbocker". It was also a term for Manhattan's aristocracy "in the early days" and became a general term, now obsolete, for a New Yorker. As a family name, it apparently comes from a family who settle in upstate New York, at a place known as the Knickerbocker Mansion in “Schaghticoke” (Algonquian for “meeting of the waters”). The mansion is under the care and restoration of the Knickerbocker Historical Society, a determined and motivated group of volunteers that rescued it from certain demolition. It’s also the site where a great legend associated with the Hudson Valley and New York originated. 
This ancient mansion, surrounded by cornfields and just south of the Hoosic River off Knickerbocker Road, was the home of the Knickerbocker family for some 250 years. Howevr, it was Washington Irving (“Dietrich Knickerbocker”) that forever branded the Knickerbocker name with the Dutch history of New York State. His relationship with NY Congressman Herman Knickerbocker (affectionately called the “Prince of Schaghticoke”), and the whole Knickerbocker family, may have been the model for Irving’s now famous satirical history of New York.
The Knickerbocker site in Schaghticoke was settled around 1700. It was Harmen Jansen van Wyhe who came to America and started the Knickerbocker line, although it was his great grandson Johannes who built the current mansion about 1770. Harmen was born about 1648, arriving in America about 1674. He called himself “van Wyekycback(e),” using that name on a land contract in 1682. He is the ancestor of all “Knickerbockers” in North America.
The origin of the name Knickerbocker (or Knickerbacker) is still a matter of conjuncture, but regardless, it became synonymous with New York’s Dutch history and made famous by Irving. Irving’s “history” of 1809 combined fact with fiction. His now famous homestead “Sunnyside” in Tarrytown, NY, is also a combination of real and imaginary. He somehow “borrowed” or purchased several items from the old Vanderheyden Palace in Albany before it was torn down.