Final answer:
The National Origins Act of 1924 was designed to curtail immigration from certain regions by creating quotas based on the 1890 census. The act received wide support at the time, even though it was discriminatory and opposed by a few. It was overturned in 1965 with the Immigration and Nationality Act.
Step-by-step explanation:
The National Origins Act of 1924 was a piece of legislation aimed at restricting immigration from Southern and Central Europe by establishing quotas based on the 1890 census. This choice of census was strategic, as the 1890 demographics were most representative of 'white' Europeans from Western Europe before the larger waves of Jews, Southern Europeans, and others arrived. Thus, the quotas effectively limited immigration of certain ethnic groups and implicitly banned Asian immigrants, as the act disallowed entry to any group ineligible for citizenship at that time.
Despite opposition from figures like congressmen Fiorello LaGuardia and Emanuel Celler, the act received broad support from labor unions and the Ku Klux Klan. Upon signing the act into law, President Calvin Coolidge infamously stated, "America must be kept American," reflecting a sentiment that equated American identity with Anglo-American whiteness. This legislative action remained in place until the Immigration and Nationality Act of 1965, which eventually dismantled these discriminatory practices, opening the United States to a broader demographic mix of immigrants from Latin America, Asia, Africa, and the Middle East.