The Alien Registration Act or Smith Act of 1940 is a United States federal statute that set criminal penalties for advocating the overthrow of the U.S. government and required all non-citizen

Citizenship

Citizenship is the state of being a citizen of a particular social, political, national, or human resource community. Citizenship status, under social contract theory, carries with it both rights and responsibilities...

 adult residents to register with the government.

The Act is best known for its use against political organizations and figures, with approximately 215 Americans indicted under terms of the legislation, including alleged communists

Communism

Communism is a social, political and economic ideology that aims at the establishment of a classless, moneyless, revolutionary and stateless socialist society structured upon common ownership of the means of production...

, Trotskyists

Trotskyism

Trotskyism is the theory of Marxism as advocated by Leon Trotsky. Trotsky considered himself an orthodox Marxist and Bolshevik-Leninist, arguing for the establishment of a vanguard party of the working-class...

, and fascists

Fascism

Fascism is a radical authoritarian nationalist political ideology. Fascists seek to rejuvenate their nation based on commitment to the national community as an organic entity, in which individuals are bound together in national identity by suprapersonal connections of ancestry, culture, and blood...

.