The years between 1890 and 1920 saw a significant shift in the regions from which immigrants came to America. Especially large groups came from Southern and Eastern Europe, and they forever changed the social, political and cultural fabric of the United States, according to the Library of Congress. Among the most prominent immigrants during this era were Italians, Poles, Greeks and Russians.
In the early- to mid-19th century, immigrants came to the United States from regions around the world. The Scots-Irish and Germans were among the most common from Europe. By mid-century, thousands of Chinese immigrants began arriving to the West Coast from Asia, many of them finding arduous work on the expanding railroads, reports Picture This, a project of the Oakland Museum of California.
By 1890, trends were shifting. In what the Library of Congress refers to as the Great Arrival, the Italian population of the United States doubled between 1880 and 1890, eventually reaching about 4 million by 1920. Similarly, Family Search reports that nearly 3.5 million Poles left their home regions during this time and settled in the United States.
These differences in immigration patterns raised ethical and religious prejudices. Many of the new immigrants were either Jewish or Catholic, and they were not always accepted by traditional Protestant Americans, according to Understanding Race, a project of the American Anthropological Association. Inclinations toward discrimination were so strong that Congress passed the Johnson-Reed Act in 1924 in an attempt to slant immigration opportunities in favor of Northern Europeans and to limit the number of people entering the United States.