Jews have been present in what is today the United States of America since the mid-17th century. However, they were small in numbers and almost exclusively Sephardic Jewish immigrants of Spanish and Portuguese ancestry.
Jewish migration to the United States increased dramatically in the early 1880s, as a result of persecution and economic difficulties in parts of Eastern Europe. Most of these new immigrants were Yiddish-speaking Ashkenazi Jews, though most came from the poor rural populations of the Russian Empire and the Pale of Settlement, located in modern-day Poland, Lithuania, Belarus, Ukraine and Moldova.
At the beginning of the 20th century, these newly arrived Jews built support networks consisting of many small synagogues and Ashkenazi Jewish Landsmannschaften (German for “Countryman Associations”) for Jews from the same town or village. American Jewish writers of the time urged assimilation and integration into the wider American culture, and Jews quickly became part of American life.