What claim was central to the nativist perspective? immigrants were un-american. immigrants brought a rich history and culture to the american culture. immigrants should become nationalized citizens and participate in political activity. americans were anarchists?

Immigrants were un-American

Nativism strongly promotes the interests of native-born citizens of a country over against those coming into the country as immigrants.

In the 19th century, the Know Nothing Party, as it was known (officially the "American Party") promoted an agenda aimed especially against immigrants from Germany and Ireland.  

Today we see evidences of nativism also in aversions to immigrants from various parts of the world coming to America.  "Build the wall!" became a prominent slogan in America's 2016 presidential campaign, appealing to those who wish to slow or stop the flow of persons coming into America from Mexico and Latin America.