The Knupp family originated in Germany. Part of the family left Germany and headed to Sweden. Another part of the family headed for England. I'm decended from the English line. If I remember correctly, a branch from the Swedish line ended up in Texas.
The Knupp name is spelled many different ways: Knupp, Knup, Canup, Canupp, Nupp, etc. Father told me our last name meant button. When I looked up German surnames, Knopf means button. There is a very good chance the family name was originally Knopf. My suspicions have been supported by other branches of the Knupp family that have traced their ancestors back to those with the last name of Knopf. There are also those decended from the Knupp family but with the spelling of Knauff, Knaugh etc. Considering that the original family name may have been Knopf, and names were spelled phonetically when given, it would explain why some family lines ended up with a version of Knupp and others with Knauff. I hope this helps in your search.