You can use census records and voter lists to see where families with the Schopper surname lived over the years.
from the New York Passengers List
The information for this chart came from the U.S. Immigration Collection at Ancestry. You can find out where the majority of the Schopper families were living before they immigrated to the U.S and learn where to focus your search for foreign records.
Immigration records can tell you an ancestor's name, ship name, port of departure, port of arrival, and destination.