Immigrants coming to the New World from Europe had to run a gauntlet of tests at Ellis Island, the main federal immigration station in the U.S. from 1892 to 1954. In charge of the tests were the officers and men of the U.S. Public Health Service.
If incoming ships showed no sign of endemic disease, they were allowed to land. Medical tests for individuals began as soon as they hefted their luggage up the stairs to the registry room: those who arrived huffing and puffing were pulled aside for further health checks. Diseases such as trachoma (an eye disease that is now rare) or other ailments considered back then to be serious and incurable would be sent back to their port of origin right away; those who were ill might have to wait until they were healthy to be admitted to the country.
The immigrants were interviewed to weed out political and social undesirables: communists, anarchists, bigamists and those who seemed too poor to support themselves (a larger problem for women and children) were turned away.

According to a 1917 U.S. Public Health Service manual, 9 out of 100 immigrants were marked with an "X" during the line inspection and were sent to mental examination rooms for further questioning. During this primary examination, doctors first asked the immigrants to answer a few questions about themselves, and then to solve simple arithmetic problems, or count backward from 20 to 1, or complete a puzzle. Out of the 9 immigrants held for this "weeding out" session, perhaps 1 or 2 would be detained for a secondary session of more extensive testing.

After the medical inspection, each immigrant filed up to the inspector's desk at the far end of the Registry Room for his or her legal examination, an experience that was often compared to the Day of Judgment. To determine an immigrant's social, economic, and moral fitness, inspectors asked rapid-fire series of questions, such as: Are you married or single? What is your occupation? How much money do you have? Have you ever been convicted of a crime? The interrogation was over in a matter of minutes after which an immigrant was either permitted to enter the United States or detained for a legal hearing.

Literacy Test: Anti-immigration forces had been trying to impose a literacy test since the 1880s as a means of restricting immigration. They finally succeeded with the Immigration Act of 1917, passed over President Woodrow Wilson's veto. This law required all immigrants, 16 years or older to read a 40-word passage in their native language. These dual-language cards were used by inspectors to test immigrants' literacy.