In 1940, Congress passed the Alien Registration Act, a national security measure that required all noncitizen adults to register with the government. In addition, the act — also known as the Smith Act — set criminal penalties for advocating the overthrow of the U.S. government.
Registration was done through the U.S. Postal Service. In the image above, newspaper publisher Toyosaku Komai is fingerprinted by Gordon Green with Frank Huber, left, assistant superintendent of mails at the Los Angeles post office, looking on.
The next morning, the Los Angeles Times reported:
Registration of Los Angeles' estimated 125,000 aliens, as required by the Alien Registration...