McCarran Internal Security Act

Legislation proposed by Senator PATRICK ANTHONY MCCARRAN and enacted by Congress in 1950 that subjected alleged members of designated Communist-action organizations to regulation by the federal government.

The McCarran Internal Security Act, also known as the Subversive Activities Control Act of 1950 (50 U.S.C.A. § 781 et seq.), was part of a legislative package that was designated as the Internal Security Act of 1950. Congress passed such statutes in response to the post-World War II COLD WAR during which many public officials perceived a threat of violent and forcible over-throw of the U.S. government by U.S. Communist groups that advocated this objective. Among other things, the legislation required members of the Communist party to register with the attorney general, and the named organizations had to provide certain information, such as lists of their members. It established the Subversive Activities Control Board to determine which individuals and organizations had to comply with the law and the procedures to be followed. Failure to satisfy the statutory requirements subjected the individual or organization to criminal prosecution and stiff fines.

Congress repealed the registration requirements of the law in 1968 as a result of a number of decisions by the U.S. Supreme Court that declared certain aspects of the law unconstitutional.