Answer:
Ellis Island is an islet located in the waters of the Hudson River, near the port of New York, although it is part of the State of New Jersey.
During the late 1800s and 1950s, the island was the main port of arrival for immigrants arriving in the United States on transatlantic ships. There, these people were examined medically and their criminal history was checked, with which, if they did not pass these tests, they were deported back to their countries of origin.
Thus, Ellis Island became a clear example of the hardening of immigration policies in America, with which it went from an almost total admission of immigrants arriving in the country to the establishment of a series of admission criteria.