The Immigration and Nationality Act of 1952 (Pub.L. 82–414, 66 Stat. 163, enacted June 27, 1952), also known as the McCarran–Walter Act, codified under Title 8 of the United States Code (8 U.S.C. ch. 12), governs immigration to and citizenship in the United States. It has been in effect since June 27, 1952. Before this Act, a variety of statutes governed immigration law but were not organized within one body of text.
This summary is from Wikipedia.