Congressman Albert Johnson and Senator David Reed were the two main architects. In the wake of intense lobbying, the Act passed with strong congressional support. There were six dissenting votes in the Senate and a handful of opponents in the House, the most vigorous of whom was freshman Brooklyn Representative Emanuel Celler. Over the succeeding four decades, Celler made the repeal of the Act into a personal crusade. Some of the law's strongest supporters were influenced by Madison Grant and his 1916 book, The Passing of the Great Race. Grant was a eugenicist and an advocate of the racial hygiene theory. His data purported to show the superiority of the founding Northern European races. But most proponents of the law were rather concerned with upholding an ethnic status quo and avoiding competition with foreign workers.
The act was strongly supported by well-known union leader and founder of the AFL, Samuel Gompers. Gompers was a Jewish immigrant, and uninterested in the accusations by many Jews that the quotas were based on anti-Semitism.
It contained two quota provisions:
In effect until June 30, 1927—set the annual quota of any quota nationality at two percent of the number of foreign-born persons of such nationality resident in the continental United States in 1890 (total quota - 164,667).
From July 1, 1927 (later postponed to July 1, 1929) to December 31, 1952—used the national origins quota system: the annual quota for any country or nationality had the same relation to 150,000 as the number of inhabitants in the continental United States in 1920 having that national origin had to the total number of inhabitants in the continental United States in 1920.
Preference quota status was established for unmarried children under 21; for parents; for spouses of U.S. citizens aged 21 and over; and for quota immigrants aged 21 and over who are skilled in agriculture, together with their wives and dependent children under age 16.
Nonquota status was accorded to: wives and unmarried children under 18 of U.S. citizens; natives of Western Hemisphere countries, with their families; nonimmigrants; and certain others. Subsequent amendments eliminated certain elements of this law’s inherent discrimination against women but comprehensive elimination was not achieved until 1952 (see the Immigration and Nationality Act of 1952).
Established the “consular control system” of immigration by mandating that no alien may be permitted entrance to the United States without an unexpired immigration visa issued by an American consular officer abroad. Thus, the State Department and the Immigration and Naturalization Service shared control of immigration.
Introduced the provision that, as a rule, no alien ineligible to become a citizen shall be admitted to the United States as an immigrant. This was aimed primarily at Japanese aliens.
Imposed fines on transportation companies who landed aliens in violation of U.S. Immigration laws.
Defined the term “immigrant” and designated all other alien entries into the United States as “nonimmigrant” (temporary visitor). Established classes of admission for nonimmigrant entries.
The Act halted "undesirable" immigration by quotas. The Act barred specific origins from the Asia-Pacific Triangle, which included Japan, China, the Philippines, Laos, Siam (Thailand), Cambodia, Singapore (then a British colony), Korea, Vietnam, Indonesia, Burma (Myanmar), India, Ceylon (Sri Lanka), Turkey, and Malaysia. Based on the Naturalization Act of 1790, these immigrants, being non-white, were not eligible for naturalization, and the Act forbade further immigration of any persons ineligible to be naturalized..
In the ten years following 1900, about 200,000 Italians immigrated annually. With the imposition of the 1924 quota, 4,000 per year were allowed. At the same time, the annual quota for Germany was over 57,000. 86% of the 165,000 permitted entries were from Northern European countries, with Germany, Britain, and Ireland with the highest quotas.
The Act set no limits on immigration from Latin America.
The quotas remained in place with minor alterations until the Immigration and Nationality Act of 1965.