Final answer:
1920s nativists would have supported the Immigration Restriction Act, reflecting their opposition to immigration from non-Western European countries and their influence on legislation like the National Origins Act of 1924.
Step-by-step explanation:
The act that 1920s nativists would have agreed to is the Immigration Restriction Act. During the 1920s, nativism in America was characterized by a strong opposition to immigration, particularly from non-Western European countries. Nativist sentiment influenced legislation such as the National Origins Act of 1924, which created quotas based on the national origins of immigrants listed in the 1890 census, effectively limiting immigration of certain groups deemed undesirable. These sentiments were also reflected in support for the Emergency Quota Act of 1921 and the broader Immigration Act of 1924.