Most of us have relatives who came from someplace other than the United States. People who come to America to live are called immigrants. From the 1850 to the early 2000s, thousands of immigrants arrived in the US and settled in New York City.
They arrived from Ireland and Germany and later from Italy, Eastern Europe, and China. Since the immigrants were poor, they settled on the lower side of Manhattan where rents for crowded apartment buildings, known as tenements were low.
Source: Immigrant Life in New York: A Local Legacy
The Library of Congress