I don't know about the surnames, that'll have to be someone else, but the Wends were a Slavic grouping that inhabited sections of what is today north-central Germany. As a distinct ethnic group, the Wends died out several hundred years ago, but that does not mean that certain families have not kept that heritage alive as part of their identities.

The term Wendish can also refer to the Sorbian language, which was spoken by Sorbs, a different Slavic group that inhabits what is today eastern Brandenburg and eastern Saxony. They are a not insignificant ethnic group in that part of Germany.

Prussians were a Baltic peoples who were conquered by Germans (in the form of the Teutonic Knights) in the Middle Ages and who inhabited the the area of what is present-day north-eastern Poland and the Kaliningrad oblast of Russia. Over the intervening centuries, the so-called Old Prussians died out, being replaced by Germans and Slavs.

All of these areas (except Saxony) were, at the time of your family's emigration from Europe, part of the much larger, predominantly German state called Prussia, which itself, became only a few years later, the largest constituent part (in terms of both land and population) of the newly created German Empire.

So it sounds like your family was/is of Slavic extraction (whether Wends or Sorbs) and Prussian nationality, or at least was of Prussian nationality at one time. For what its worth, the town of Werben (officially the Hanseatic City of Werben) lies in the current state of Saxony-Anhalt and would tend to give credence to the idea that your family comes from the group known as the Wends rather than [or] the Sorbs.

edit: grammar and corrections.