Answer:
Nativists
Step-by-step explanation:
Nativists are a group of people who believed that the descendants from the dwellers of the original British thirteen colonies are the real Americans. It is understood that the original European settlers in the British thirteen colonies are from Western Europe. These are predominantly the descendants of the people from Britain, France, Spain, the Netherland, and Germany.
Hence, the group that believed that only long-ago immigrants from Western Europe could become real Americans are the NATIVISTS.