The Alien Registration Act, passed by Congress in 1940, required that all persons who were not citizens or nationals of the United States and were living within U.S. borders go to the local post office and register their alien status with the government. The Act made it illegal for any resident or citizen of the United States of America to teach or advocate the violent overthrow of the U.S. government.
According to Carl Rice, in her 1963 doctorate thesis, there was concern about foreign influences in America. Post World War I sentiment, the results of the Great Depression among citizens and the geopolitical unrest in Europe, created “A fear of revolutionary ideas and possible seditious* activities…”.
The registration process included filling out a questionnaire and having fingerprints taken. The Alien Registration Form (Form AR-2) contained 15 questions. These included questions about when and where the subject was born, when and where he or she entered the United States, and a physical description. There were also questions about employment, organization memberships, prior military service, and attempts to obtain naturalization in the United States. As the Immigration and Naturalization Service (INS) received the forms, it assigned an Alien Registration Number (for example, A1234567). The INS mailed an Alien Registration Receipt Card with this number to each registrant as proof of alien status.
*Inciting or causing people to rebel against the authority of a state or country.