many Americans resent it and discriminated against the new immigrants to the u.s. what was this anti-foreign attitude called

Answer:

Nativism

Explanation:

The Nativism was a policy that was implemented by the US to protect the interests of the native-born or established inhabitants of the country against those of the immigrants. In other words, the policy was  a semi-discriminatory policy. The policy became a general ground for the opposition to immigration based on the unfounded fear that immigrants would spoil the pure American culture. Nativism was about preserving cultural change.