It would seem that the United States (colonial & federal) has always been composed of hyphenated Americans. Germans settled together during colonial times in geographical areas, as did the Irish, Scotish, English. What kept these groups from being isolated from each other was the availability of land for expansion. Economic necessity required people to associate on an individual basis on the frontier. This further discouraged conclaves of ethnic communities.
The immigration in the late 1800s temporarily created isolated groups of people (Swedes, Jews, Italians, Russians) but they were again dispersed across the country and assimilated because of economic activity.
I do believe that hypnenated Americans are no threat to the American way of life except if a group is not an economic participant, if they are isolated, if they are not mobile. It is their self-concept that will keep them separate.
