Taken directly from their site,
Kashubian History
"An area in present North Central Poland stretching West from Gdansk about 70 miles. From the Baltic south to about Wiele, a rather remote part of the country which enabled that different language, Kashubian, to be used yet today.
During the time of the mass migration of Kashubians 1850's to 1890's, the Kashubian language was forbidden to be taught or spoken as the land was under Prussian domination. It is now legal to be taught in schools and spoken openly."
The site goes on to say that after spending sometime in Winona, many of these immigrants moved to Pine Creek or Dodge, Wisconsin (both places where my father grew up) with some of the family moving to Montana.