Why does the U. S. continue its attempts to limit immigration?

In all of its parts, the most basic purpose of the 1924 Immigration Act was to preserve the ideal of U.S. homogeneity,” the State Department history page concludes. During the 1940s and 50s, the U.S. made some policy changes that increased – however slightly – the number and nationalities of immigrants.

would not cooperate with each other voluntarily.