At the time of the Declaration of Independence (1776), there were already 1,500 to 2,500 Jews in the British colonies that would become the United States, mostly descendants of Sephardic immigrants from Spain, Portugal, or their colonies.
In the wake of large immigration from Germany in the middle of the 19th century, the new arrivals bolstered the Jewish population from 6,000 in 1826 to 15,000 in 1840 and 280,000 in 1880. Then, most Jews were part of the educated and largely secular Ashkenazi (German) community, although a minority population of the older Sephardic Jewish families remained prominent.
Beginning in 1881, a wave of immigration from the Russian Empire and other parts of Eastern Europe started, and by the turn of the century, the American Jewish population had surpassed one million. That immigration continued until the imposition, in 1924, of strict quotas designed to restrict the entry of new immigrants from eastern and southern Europe. Until that time, the United States absorbed about two-thirds of the total number of Jewish emigrants leaving eastern Europe. By 1918, America had become the country with the largest Jewish community in the world.
Most of these new arrivals were also Yiddish-speaking Ashkenazi Jews who came from the poor rural populations of the Russian Empire – what is today Poland, Lithuania, Belarus, Ukraine, and Moldova. Over two million Jews arrived between the mid-1800s and 1924. Most settled in New York City and its immediate environs, establishing what became one of the world's major concentrations of the Jewish population.
Jewish immigrants dreamed of the United States as a promised land, a "goldene medina", but the reality was often harsh. Most newcomers worked at manual labor in appalling conditions. The largest concentration was in New York's Lower East Side, which at one time was home to over 350,000 Jews crammed into a single square mile.
These newly arrived Jews built support networks consisting of many small synagogues and Ashkenazi "Landsmannschaften", associations of Jews coming from the same town or village in Europe. Jewish writers of the time urged assimilation and integration into the wider American culture, and Jews quickly became part of American life. Later, many Jews entered the free professions, and Jews distinguished themselves in commerce, industry, and science.
In the 1930s, only a small fraction of the Jewish refugees clamoring to escape the threat of Nazism were admitted. By 1940, the Jewish population had risen to 4,500,000, and that number increased after the war when many Holocaust survivors arrived on American shores. Half a million American Jews (half of all Jewish men aged between 18 and 50) fought in World War II.
Many Jews left the cities for the suburbs which facilitated the formation of new Jewish centers. Jewish day school enrollment more than doubled between the end of World War II and the mid-1950s, while synagogue affiliation jumped from 20 percent in 1930 to 60 percent thirty years later. More recent waves of Jewish immigration from Russia and other regions have largely joined the mainstream American Jewish community.
Jews have served and continue to serve prominently in all areas of US public life, including Congress, the US Supreme Court and other courts, and federal and state government.
Over the last decades, many Israelis immigrated to the United States, as have 150,000 Jews from the FSU, 30,000 Jews from Iran, and thousands of others from Latin America and South Africa, and other states and regions.
