Nissen
A common North German and Danish surname, most often a patronymic meaning “son of Nisse.”
The #6,796 most common surname in the United States (2010 Census) — about 1 in every 62,197 Americans shares it.
Etymology
Nissen is best understood as a patronymic formed from the personal name Nisse or Nisse/ Nissek, a northern diminutive or pet form related to names like Niels (Nicholas). In that system, the ending -sen means “son of,” so the surname originally meant “son of Nisse.” The name is especially characteristic of Danish and northern German naming traditions, where -sen surnames are very common.
History
The surname is especially concentrated in Denmark and in the German border regions of Schleswig and Holstein, where -sen family names are historically very frequent. The historical sources you provided mainly use Nissen as an example of this northern naming pattern rather than defining it directly. In modern usage it remains a well-established Danish and North German surname, and it also appears in North America through later migration.
Origin
Regions
Variant spellings
Fun fact
The same -sen pattern that gives Nissen also produces very common surnames such as Hansen and Thomsen in Denmark and northern Germany.
From the historical record
“dahin mehr vereinzelten Zusammensetzungen auf -sen, je weiter nach Norden, desto stärker hervor, namentlich im Herzogtum Schleswig, bis in den Kreisen Husum und Tondem die Hansen, Thomsen und Nissen^ Chri- stiansen und Oidionsen^ Deilefsen und Himichsen alles so überwuchern, daß sie fast 90 v. H. aller…”
— Die deutschen Familiennamen